Resolve pending commit links in MIL-004 review records

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -0,0 +1,26 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+      - name: Install
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install -e ".[dev]"
+      - name: Tests
+        run: python -m pytest
+      - name: Lint
+        run: python -m ruff check src tests
+      - name: Format check
+        run: python -m ruff format --check src tests
+      - name: Types
+        run: python -m mypy src tests

README.md

@@ -1,2 +1,113 @@
-# 015-coffee_machine
+# Coffee Machine
 
+A console game from Udemy's *100 Days of Code: The Complete Python Pro Bootcamp*
+(day 15). A virtual coffee machine serves espresso, latte and cappuccino. Pay with
+US coins (quarters, dimes, nickels and pennies). The machine checks its water, milk
+and coffee before it serves, refunds you if you pay too little and gives change if
+you pay too much.
+
+```
+What would you like? (espresso/latte/cappuccino): latte
+Please insert coins.
+How many quarters?: 10
+How many dimes?: 0
+How many nickels?: 0
+How many pennies?: 0
+Here is your latte. Enjoy!
+```
+
+- Python 3.13 or newer, no runtime dependencies.
+- Type `report` to see the water, milk, coffee and money in the machine, and `off`
+  to switch the machine off.
+- The function names follow the assignment: `is_resource_sufficient`,
+  `process_coins`, `is_transaction_successful`, `make_coffee`.
+- Money is counted in whole cents inside the program, so change is never off by a
+  rounding error.
+
+## Requirements
+
+- [Python](https://www.python.org/downloads/) 3.13 or newer
+- Optional: [Doxygen](https://www.doxygen.nl/) to build the source documentation
+
+## Set up
+
+Create a local virtual environment in `.venv`, activate it, and upgrade `pip`.
+
+Windows (PowerShell):
+
+```powershell
+python -m venv .venv
+.venv\Scripts\Activate.ps1
+python -m pip install --upgrade pip
+```
+
+Windows (Git Bash), Linux and macOS:
+
+```bash
+python -m venv .venv
+source .venv/Scripts/activate   # Linux/macOS: source .venv/bin/activate
+python -m pip install --upgrade pip
+```
+
+The machine itself needs nothing more. To run the tests and the code checks, install
+the development tools:
+
+```bash
+python -m pip install -e ".[dev]"
+```
+
+## Run the coffee machine
+
+```bash
+python -m coffee_machine
+```
+
+Type `espresso`, `latte` or `cappuccino` and press Enter, then enter the coins.
+Type `report` for the machine's resources, or `off` to quit.
+
+## Run the tests
+
+```bash
+python -m pytest
+```
+
+Check the code style and types:
+
+```bash
+python -m ruff check src tests
+python -m ruff format --check src tests
+python -m mypy src tests
+```
+
+## Continuous integration
+
+On every push and pull request, `.gitea/workflows/ci.yml` installs the project on
+Python 3.13 and runs the same checks as above: `pytest`, `ruff check`,
+`ruff format --check` and `mypy`. To run all of them locally:
+
+```bash
+python -m pytest && python -m ruff check src tests && python -m ruff format --check src tests && python -m mypy src tests
+```
+
+## Build the source documentation
+
+The source uses Doxygen comments. The HTML output goes to `docs/doxygen/html`.
+
+```bash
+doxygen Doxyfile
+```
+
+## Project layout
+
+| Path | Content |
+| --- | --- |
+| `src/coffee_machine/` | The machine: `main.py` (the loop), `constants.py` (menu, coins, starting resources) |
+| `tests/` | pytest tests |
+| `docs/` | Planning and review documents (business case, plan, milestones) |
+| `pyproject.toml` | Project configuration |
+| `Doxyfile` | Doxygen configuration |
+| `.gitea/workflows/` | CI workflow |
+
+## License
+
+GNU Affero General Public License v3.0. See [LICENSE](LICENSE).

docs/artifact-registry.md

@@ -1,43 +1,45 @@
-# Artifact Registry
+# Artifact Registry
-
+
-This project's artifact state. Types, short names and `CrossReference
+This project's artifact state. Types, short names and `CrossReference
-Candidates` come from the framework catalog
+Candidates` come from the framework catalog
-(`framework/registry/artifact-catalog.md`); this file only records where
+(`framework/registry/artifact-catalog.md`); this file only records where
-each document lives in *this* project and the next version to use.
+each document lives in *this* project and the next version to use.
-
+
-Delete rows for types you don't use. Add a row the first time you create a
+Delete rows for types you don't use. Add a row the first time you create a
-document of a type. `Primary File` may contain a glob (e.g.
+document of a type. `Primary File` may contain a glob (e.g.
-`docs/uc-*/uc.md`); `framework/scripts/find-crossreferences.sh` reads it.
+`docs/uc-*/uc.md`); `framework/scripts/find-crossreferences.sh` reads it.
-
+
-| Short Name | Artifact Type | Primary File | Next Available Version |
+| Short Name | Artifact Type | Primary File | Next Available Version |
-| --- | --- | --- | --- |
+| --- | --- | --- | --- |
-| BC | Business Case | docs/business-case.md | 002 |
+| BC | Business Case | docs/business-case.md | 002 |
-| SA | Stakeholder Analysis | docs/stakeholder-analysis.md | 002 |
+| SA | Stakeholder Analysis | docs/stakeholder-analysis.md | 002 |
-| PP | Project Plan | docs/project-plan.md | 002 |
+| PP | Project Plan | docs/project-plan.md | 002 |
-| MIL | Milestone / Gateway | docs/milestones/*.md | 004 |
+| MIL | Milestone / Gateway | docs/milestones/*.md | 005 |
-
+| RC | SQA Review Record | docs/sqa/reviews/rc-*.md | 008 |
-## Languages
+| TM | Traceability Matrix | docs/sqa/traceability-matrix.md | 002 |
-
+
-Set the PO language when the project starts; `project-planning` asks for it
+## Languages
-if it is missing. A translated artifact is named `<artifact>.<language>.md`
+
-(for example `business-case.da.md`); the English file stays the source.
+Set the PO language when the project starts; `project-planning` asks for it
-
+if it is missing. A translated artifact is named `<artifact>.<language>.md`
-| Setting | Value |
+(for example `business-case.da.md`); the English file stays the source.
-| --- | --- |
+
-| PO language | en |
+| Setting | Value |
-| High-level register | IT Executive English |
+| --- | --- |
-| Technical register | IT Professional English |
+| PO language | en |
-
+| High-level register | IT Executive English |
-| Artifact types | Register | Also kept as a PO-language file |
+| Technical register | IT Professional English |
-| --- | --- | --- |
+
-| BC, KPI, PP, MIL | IT Executive English | Yes |
+| Artifact types | Register | Also kept as a PO-language file |
-| SA, BMC, BPMN, UCD, US, UC, SSD, DM, RA, GOV, DICT | IT Professional English | Yes |
+| --- | --- | --- |
-| OC, SD, DCD, ERD, ADR, TM, RC, QC, source code | IT Professional English | No |
+| BC, KPI, PP, MIL | IT Executive English | Yes |
-
+| SA, BMC, BPMN, UCD, US, UC, SSD, DM, RA, GOV, DICT | IT Professional English | Yes |
-## Notes
+| OC, SD, DCD, ERD, ADR, TM, RC, QC, source code | IT Professional English | No |
-
+
-- "Next Available Version" is the zero-padded (3-digit) version to use the
+## Notes
-  *next* time a new document of that type is created. Increment it only when
+
-  a brand-new document is created, not when an existing document's
+- "Next Available Version" is the zero-padded (3-digit) version to use the
-  `## Version History` gets a row.
+  *next* time a new document of that type is created. Increment it only when
-- `ADR` uses 4 digits (`0001`); `RC` is sequential across all artifact types.
+  a brand-new document is created, not when an existing document's
+  `## Version History` gets a row.
+- `ADR` uses 4 digits (`0001`); `RC` is sequential across all artifact types.

docs/business-case.md

@@ -9,7 +9,8 @@
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-05 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | [c0c3940] |
+| 2026-10-06 | Accepted | Jens Tirsvad Nielsen | S01 | Added duration constraint (RC-001 action) | [8ef00aa] |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Added objective 6 and scope for code review and CI | [8ef00aa] |
 
 ---
 
@@ -45,6 +46,7 @@ participants and for viewers browsing the repository.
 3. Cover the behaviour with automated pytest tests.
 4. Document how to set up a local `.venv` and run the program and tests.
 5. Publish the repository with a description, topics and README.
+6. Review the source code against the Python quality checklist and run the tests and code checks automatically on every push.
 
 ## Scope
 
@@ -55,6 +57,7 @@ participants and for viewers browsing the repository.
 - `pyproject.toml`, Python `.gitignore`, `Doxyfile`, `README.md`.
 - Project documents under `docs/`.
 - Repository description and topics on the git host.
+- A review record for the source code and a CI workflow (MIL-004).
 
 ### Out of Scope
 
@@ -109,6 +112,7 @@ professional project hygiene, and the goal of sharing readable solutions.
 - Constants live in `constants.py`.
 - Source files use Doxygen comments.
 - Nothing is committed or pushed unless the user asks.
+- Duration: one week, 2026-10-05 to 2026-10-12.
 
 ## Cost–Benefit Assessment
 
@@ -131,4 +135,4 @@ Proceed — the scope is small, well specified and delivers a reusable example.
 ---
 
 [SA-001]: ./stakeholder-analysis.md
-[c0c3940]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/c0c3940551db0d7d96492cc734976d0436051ff9
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/milestones/mil-004-code-review-and-ci.md

@@ -0,0 +1,70 @@
+# MIL-004 Code Review and CI
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | MIL-004 |
+| CrossReference | [BC-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Purpose
+
+Decide whether the source code has been reviewed against the Python quality checklist and is checked automatically on every push.
+
+## Deliverable
+
+`RC-006` review record for the source code, fixes for its findings, a CI workflow running the tests and code checks, and a README section describing it.
+
+## Go / No-Go Criteria
+
+| # | Criterion (objectively checkable) | Go | No-Go |
+| --- | --- | --- | --- |
+| 1 | `docs/sqa/reviews/` has an RC record for the source against `QC-PY-001` | Present with a verdict | Missing |
+| 2 | Every Fail in that record has a closed action item or a recorded deviation | All handled | Open Fail |
+| 3 | The CI workflow runs pytest, ruff check, ruff format --check and mypy on push and pull request | All four run | Any missing |
+| 4 | The latest CI run on `main` is green | Green | Red or none |
+| 5 | README describes the CI and the matching local commands | Present | Missing |
+
+## Dependencies
+
+| Depends on | Reason |
+| --- | --- |
+| MIL-003 | Tests and metadata must exist before they are reviewed and automated |
+
+## Traceability
+
+| Business Case objective / KPI / user story | Reference |
+| --- | --- |
+| Objective 6 (review and CI), Objective 4 | [BC-001] |
+
+## Ownership
+
+| Role | Stakeholder ID (SA) |
+| --- | --- |
+| Owner | S01 |
+| Approving reviewer | S01 |
+
+## Target Date
+
+2026-10-12 — inside the duration constraint in [BC-001].
+
+## Tasks
+
+| # | Task | Summary | Needs its own Use Case/User Story? | Reference |
+| --- | --- | --- | --- | --- |
+| 1 | Review source code against QC-PY-001 | Create RC-006 with `new-artifact.sh RC` for `src/` and `tests/` against `framework/qc/qc-programming-python.md`. Criterion 10 (Design Class Diagram) is N-A because no DCD exists. Every Fail becomes an action item. | No | Objective 6 |
+| 2 | Fix code review findings | Fix each Fail from RC-006 under `src/` and `tests/`, or record a justified deviation in the record. If the review has no Fail, close this task without a code change. | No | Objective 6 |
+| 3 | Add CI workflow | Add `.gitea/workflows/ci.yml` that sets up Python 3.13, installs `.[dev]`, and runs `pytest`, `ruff check`, `ruff format --check` and `mypy` on push and pull request. Check first that the git host has an Actions runner. | No | Objective 6 |
+| 4 | Document CI in README | Add a short section to README.md saying what the CI runs and how to run the same checks locally. | No | Objective 4 |
+| 5 | Update traceability matrix | Add the RC-006 review to `docs/sqa/traceability-matrix.md` and close the milestone's row there. | No | Objective 6 |
+
+---
+
+[BC-001]: ../business-case.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/project-plan.md

@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | PP-001 |
-| CrossReference | [BC-001], [SA-001], [MIL-001], [MIL-002], [MIL-003] |
+| CrossReference | [BC-001], [SA-001], [MIL-001], [MIL-002], [MIL-003], [MIL-004] |
 
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-05 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | [c0c3940] |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Added MIL-004 Code Review and CI | [8ef00aa] |
 
 ---
 
@@ -31,6 +32,7 @@ published project, within the short assignment timeline in [BC-001].
 | Project Setup | [MIL-001] | 2026-10-05 to 2026-10-07 | 2026-10-07 | S01 | none | Skeleton, tooling, README | [Milestone 40] |
 | Coffee Machine Core | [MIL-002] | 2026-10-08 to 2026-10-10 | 2026-10-10 | S01 | none | Working program | [Milestone 41] |
 | Quality and Publication | [MIL-003] | 2026-10-11 to 2026-10-12 | 2026-10-12 | S01 | none | Tests, Doxygen, published repo | [Milestone 42] |
+| Code Review and CI | [MIL-004] | 2026-10-07 to 2026-10-12 | 2026-10-12 | S01 | none | Source review record, CI workflow | [Milestone 48] |
 
 ```plantuml
 @startgantt
@@ -41,6 +43,8 @@ Project starts 2026-10-05
 [MIL-001 Go/No-Go] happens 2026-10-07
 [MIL-002 Go/No-Go] happens 2026-10-10
 [MIL-003 Go/No-Go] happens 2026-10-12
+[Code Review and CI] starts 2026-10-07 and ends 2026-10-12
+[MIL-004 Go/No-Go] happens 2026-10-12
 @endgantt
 ```
 
@@ -53,11 +57,12 @@ Project starts 2026-10-05
 | `pyproject.toml`, `.gitignore`, `Doxyfile`, README | [MIL-001] |
 | Project documents | Planning, before [MIL-001] |
 | Repository description and topics | [MIL-003] |
+| Source code review record and CI workflow | [MIL-004] |
 
 ## Dependencies
 
 ```
-MIL-001 -> MIL-002 -> MIL-003
+MIL-001 -> MIL-002 -> MIL-003 -> MIL-004
 ```
 
 A No-Go moves all later dates by the same amount.
@@ -66,6 +71,7 @@ A No-Go moves all later dates by the same amount.
 
 | Risk | Impact | Mitigation |
 | --- | --- | --- |
+| The git host has no Actions runner | CI cannot run | Check the host first; if none, keep the workflow file and document the local commands |
 | README template not supplied | README task blocked | Ask S01 for the template before the task |
 | Doxygen not installed locally | Cannot verify docs | Document the install step in README |
 
@@ -82,7 +88,10 @@ A No-Go moves all later dates by the same amount.
 [MIL-001]: ./milestones/mil-001-project-setup.md
 [MIL-002]: ./milestones/mil-002-coffee-machine-core.md
 [MIL-003]: ./milestones/mil-003-quality-and-publication.md
+[MIL-004]: ./milestones/mil-004-code-review-and-ci.md
 [Milestone 40]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/milestone/40
 [Milestone 41]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/milestone/41
 [Milestone 42]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/milestone/42
 [c0c3940]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/c0c3940551db0d7d96492cc734976d0436051ff9
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d
+[Milestone 48]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/milestone/48

docs/sqa/reviews/rc-001-business-case.md

@@ -0,0 +1,49 @@
+# RC-001 Business Case Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-001 |
+| CrossReference | [BC-001], [QC-BC-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [BC-001] (docs/business-case.md)
+- Checklist used: [QC-BC-001] (`QC-BC-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The documents were drafted by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | ROI/Cost-Benefit analysis is quantitative, or where qualitative, is explicitly justified | Pass | Cost-Benefit table is explicitly qualitative and says why (no money involved). |
+| 2 | Risks are identified with documented impact and mitigation | Pass | Three risks, each with impact and mitigation. |
+| 3 | Success criteria are measurable, stating explicit targets rather than vague aspirations | Pass | Five criteria with targets and a measure each. |
+| 4 | Scope explicitly separates In Scope vs Out of Scope | Pass | `### In Scope` and `### Out of Scope` are separate. |
+| 5 | Stakeholders are cross-referenced to Stakeholder Analysis IDs rather than re-described inline | Pass | Stakeholders table cites S01 to S03 only; no roles are re-described. |
+| 6 | Methodology and quality-standard foundation are stated explicitly (e.g. ISO/IEC 25010, Larman) | Pass | Methodology section names the framework, ISO/IEC 25010:2023 and the coding conventions. |
+| 7 | Assumptions and constraints are explicit and clearly distinguished from one another | Pass | Fixed in v2: the first draft had no duration, although MIL-001 to MIL-003 and PP-001 cite one. Constraints now state 2026-10-05 to 2026-10-12. |
+| 8 | Document supports executive decision-making with a clear, unambiguous recommendation | Pass | Recommendation is a single "Proceed" with a reason. |
+
+## Overall Verdict
+
+Go — all mandatory criteria pass. Criterion 7 first failed (missing duration constraint) and was fixed in the same change as BC-001 v2.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| Add the duration constraint to BC-001 (done in v2) | S01 | 2026-10-06 |
+
+---
+
+[BC-001]: ../../business-case.md
+[QC-BC-001]: ../../../framework/qc/qc-business-case.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/sqa/reviews/rc-002-stakeholder-analysis.md

@@ -0,0 +1,49 @@
+# RC-002 Stakeholder Analysis Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-002 |
+| CrossReference | [SA-001], [QC-SA-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [SA-001] (docs/stakeholder-analysis.md)
+- Checklist used: [QC-SA-001] (`QC-SA-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The documents were drafted by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | Power/Interest grid is filled for every stakeholder, with no gaps or unclassified entries | Pass | S01 to S03 each have power, interest and quadrant. |
+| 2 | Each stakeholder is assigned a unique, stable ID (e.g. S01-S11 style) reusable for RACI assignments in other artifacts | Pass | IDs S01 to S03 are used by every other document. |
+| 3 | Roles and organizational context are defined with explicit Power and Interest levels, not just narrative description | Pass | Levels are stated as High/Low in the table, with organisation and role. |
+| 4 | Communication needs (channel, frequency, deliverable type) are mapped to project phases or milestones | Pass | Communication table maps each stakeholder to MIL-001 to MIL-003. |
+| 5 | Conflicting stakeholder interests are identified with documented mitigation or resolution strategies | Pass | One conflict (assignment names vs testable structure) with a mitigation. |
+| 6 | Stakeholder concerns are explicitly traced to Business Case objectives | Pass | Traceability table maps each stakeholder to [BC-001] objectives. |
+| 7 | Primary concerns are expressed in both business language and a recognized quality-attribute mapping (e.g. FURPS+) | Pass | Each concern has a FURPS+ attribute. |
+| 8 | Document is understandable and navigable by non-technical stakeholders reviewing their own entry | Pass | Plain language, short; each stakeholder can find their own row. |
+
+## Overall Verdict
+
+Go — all criteria pass. The Sign-Off row said `Pending review` and was updated to the Go in SA-001 v2.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| Record the sign-off in SA-001 (done in v2) | S01 | 2026-10-06 |
+
+---
+
+[SA-001]: ../../stakeholder-analysis.md
+[QC-SA-001]: ../../../framework/qc/qc-stakeholder-analysis.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/sqa/reviews/rc-003-mil-001.md

@@ -0,0 +1,47 @@
+# RC-003 MIL-001 Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-003 |
+| CrossReference | [MIL-001], [QC-MIL-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [MIL-001] (docs/milestones/mil-001-project-setup.md)
+- Checklist used: [QC-MIL-001] (`QC-MIL-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The documents were drafted by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | A concrete deliverable is defined for every gate | Pass | Deliverable section names the concrete output. |
+| 2 | Explicit Go/No-Go criteria are stated for each gate | Pass | Go/No-Go table with one checkable criterion per row. |
+| 3 | Dependencies on other milestones are explicitly mapped | Pass | Dependencies table present. |
+| 4 | Each milestone is traceable to a Business Case objective or KPI | Pass | Traceability cites the Business Case objectives. |
+| 5 | Milestone owner and approving reviewer are identified | Pass | Ownership names S01 as owner and approving reviewer (same person; see independence note). |
+| 6 | Milestone has a defined target date consistent with project constraints | Pass | Target date lies inside the duration constraint added to BC-001 in RC-001's action (2026-10-05 to 2026-10-12). Before that fix this was a Fail. |
+
+## Overall Verdict
+
+Go — all criteria pass. Delivery matches: issues #1 to #5 closed, PRs 19 and 20 merged.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| None | S01 | - |
+
+---
+
+[MIL-001]: ../../milestones/mil-001-project-setup.md
+[QC-MIL-001]: ../../../framework/qc/qc-milestones-gateways.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/sqa/reviews/rc-004-mil-002.md

@@ -0,0 +1,47 @@
+# RC-004 MIL-002 Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-004 |
+| CrossReference | [MIL-002], [QC-MIL-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [MIL-002] (docs/milestones/mil-002-coffee-machine-core.md)
+- Checklist used: [QC-MIL-001] (`QC-MIL-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The documents were drafted by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | A concrete deliverable is defined for every gate | Pass | Deliverable section names the concrete output. |
+| 2 | Explicit Go/No-Go criteria are stated for each gate | Pass | Go/No-Go table with one checkable criterion per row. |
+| 3 | Dependencies on other milestones are explicitly mapped | Pass | Dependencies table present. |
+| 4 | Each milestone is traceable to a Business Case objective or KPI | Pass | Traceability cites the Business Case objectives. |
+| 5 | Milestone owner and approving reviewer are identified | Pass | Ownership names S01 as owner and approving reviewer (same person; see independence note). |
+| 6 | Milestone has a defined target date consistent with project constraints | Pass | Target date lies inside the duration constraint added to BC-001 in RC-001's action (2026-10-05 to 2026-10-12). Before that fix this was a Fail. |
+
+## Overall Verdict
+
+Go — all criteria pass. Delivery matches: issues #6 to #12 closed, PR 21 merged. Note: Go/No-Go rows refer to the assignment's behaviour; the exact texts are asserted in tests/.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| None | S01 | - |
+
+---
+
+[MIL-002]: ../../milestones/mil-002-coffee-machine-core.md
+[QC-MIL-001]: ../../../framework/qc/qc-milestones-gateways.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/sqa/reviews/rc-005-mil-003.md

@@ -0,0 +1,47 @@
+# RC-005 MIL-003 Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-005 |
+| CrossReference | [MIL-003], [QC-MIL-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [8ef00aa] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [MIL-003] (docs/milestones/mil-003-quality-and-publication.md)
+- Checklist used: [QC-MIL-001] (`QC-MIL-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The documents were drafted by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | A concrete deliverable is defined for every gate | Pass | Deliverable section names the concrete output. |
+| 2 | Explicit Go/No-Go criteria are stated for each gate | Pass | Go/No-Go table with one checkable criterion per row. |
+| 3 | Dependencies on other milestones are explicitly mapped | Pass | Dependencies table present. |
+| 4 | Each milestone is traceable to a Business Case objective or KPI | Pass | Traceability cites the Business Case objectives. |
+| 5 | Milestone owner and approving reviewer are identified | Pass | Ownership names S01 as owner and approving reviewer (same person; see independence note). |
+| 6 | Milestone has a defined target date consistent with project constraints | Pass | Target date lies inside the duration constraint added to BC-001 in RC-001's action (2026-10-05 to 2026-10-12). Before that fix this was a Fail. |
+
+## Overall Verdict
+
+Go — all criteria pass. Delivery matches: issues #13 to #17 closed, PR 22 merged.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| None | S01 | - |
+
+---
+
+[MIL-003]: ../../milestones/mil-003-quality-and-publication.md
+[QC-MIL-001]: ../../../framework/qc/qc-milestones-gateways.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

docs/sqa/reviews/rc-006-source-code.md

@@ -0,0 +1,54 @@
+# RC-006 Source Code Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-006 |
+| CrossReference | [MIL-004], [QC-PY-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [00d47e2] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: `src/coffee_machine/` and `tests/` at the state of MIL-003 (`main` after PR 22)
+- Checklist used: [QC-PY-001] (`QC-PY-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The code and documents were written by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | Packages, modules, functions, variables, classes and constants follow PEP 8 casing (`snake_case`, `PascalCase`, `UPPER_SNAKE`) | Pass | Modules, functions and variables are `snake_case`, constants `UPPER_SNAKE`, `Drink` is `PascalCase`. |
+| 2 | Names state purpose in the domain's language; no unexplained abbreviations, no single-letter names outside tiny scopes | Pass | Names state purpose (`is_resource_sufficient`, `process_coins`); the only short names are loop variables. |
+| 3 | Code is produced by the project's formatter and passes its linter with no unexplained suppressions | Pass | `ruff check` and `ruff format --check` pass; no suppression comments. |
+| 4 | Every function and method signature is type-annotated, including `-> None` | Pass | Every function, including tests and the nested `feed`, is annotated. |
+| 5 | No bare `except:`, no swallowed exceptions; specific exceptions are raised and the cause is kept (`raise ... from`) | Pass | No bare `except`. `_ask_coin_count` catches only `ValueError` and answers it by asking again, so nothing is swallowed. |
+| 6 | No mutable default arguments and no shadowed builtins | Pass | No mutable defaults; no builtin is shadowed. |
+| 7 | Files, locks and connections are managed with context managers | N-A | The program opens no files, locks or connections. |
+| 8 | Public modules, classes and functions have docstrings that say what, not how | Pass | All modules, public functions and tests have Doxygen docstrings that say what the code does. |
+| 9 | Logging uses `logging`, not `print`; no secrets or personal data in log output | N-A | No logging exists. `print` is the program's own console output, not diagnostics. |
+| 10 | Classes and operations trace to the Design Class Diagram they implement; deviations are recorded | N-A | No Design Class Diagram exists; the plan treats the work as plain technical tasks. |
+| 11 | Tests exist for new behaviour, are named for the behaviour, and do not depend on order or the network | Pass | 19 tests named for behaviour, independent of order, no network. |
+| 12 | Type checker runs in strict mode without errors; `Any` is justified in a comment | Pass | `mypy --strict` runs clean and `Any` is not used. |
+| 13 | Dependencies are declared and pinned in the project's dependency file, none unused | Fail | Runtime dependencies: none. The dev tools had no lower bounds for ruff and mypy; fixed by action item 1, which sets `pytest>=9`, `ruff>=0.16`, `mypy>=2.4` (the tested versions). |
+
+## Overall Verdict
+
+Go — every mandatory criterion passes or is N-A. The one Fail (13) is optional and is fixed in the same change by issue #25.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| Set lower bounds for the dev dependencies in pyproject.toml (done) | S01 | 2026-10-06 |
+
+---
+
+[MIL-004]: ../../milestones/mil-004-code-review-and-ci.md
+[QC-PY-001]: ../../../framework/qc/qc-programming-python.md
+[00d47e2]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/00d47e244c82007bbc55e18312649189b175ec10

docs/sqa/reviews/rc-007-mil-004.md

@@ -0,0 +1,47 @@
+# RC-007 MIL-004 Review
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | RC-007 |
+| CrossReference | [MIL-004], [QC-MIL-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [00d47e2] |
+
+---
+
+## Artifact Under Review
+
+- Instance reviewed: [MIL-004] (docs/milestones/mil-004-code-review-and-ci.md)
+- Checklist used: [QC-MIL-001] (`QC-MIL-001`)
+- Independence: S01 is the only stakeholder and is also the recorded author, so the reviewer-is-not-author rule cannot be met. The code and documents were written by Claude on S01's behalf; S01 reviews and signs. This is a known limit of a one-person project, not a clean independent review.
+
+## Checklist Results
+
+| # | Criterion | Status | Evidence/Notes |
+| --- | --- | --- | --- |
+| 1 | A concrete deliverable is defined for every gate | Pass | Deliverable names the RC record, the fixes, the CI workflow and the README section. |
+| 2 | Explicit Go/No-Go criteria are stated for each gate | Pass | Five Go/No-Go rows, each checkable (a record exists, a workflow runs four commands, a run is green). |
+| 3 | Dependencies on other milestones are explicitly mapped | Pass | Depends on MIL-003 with a reason. |
+| 4 | Each milestone is traceable to a Business Case objective or KPI | Pass | Traceability cites Business Case objective 6 and 4. |
+| 5 | Milestone owner and approving reviewer are identified | Pass | Owner and approving reviewer are S01 (same person; see independence note). |
+| 6 | Milestone has a defined target date consistent with project constraints | Pass | Target date 2026-10-12 lies inside the duration constraint in the Business Case. |
+
+## Overall Verdict
+
+Go — all criteria pass.
+
+## Action Items
+
+| Action | Owner | Due |
+| --- | --- | --- |
+| None | S01 | - |
+
+---
+
+[MIL-004]: ../../milestones/mil-004-code-review-and-ci.md
+[QC-MIL-001]: ../../../framework/qc/qc-milestones-gateways.md
+[00d47e2]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/00d47e244c82007bbc55e18312649189b175ec10

docs/sqa/traceability-matrix.md

@@ -0,0 +1,59 @@
+# Traceability Matrix
+
+## Metadata
+| Key | Value |
+| --- | --- |
+| ID | TM-001 |
+| CrossReference | [BC-001] |
+
+## Version History
+| Date | Status | Author | Reviewer | Change | Commit |
+| --- | --- | --- | --- | --- | --- |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Added MIL-004 | [8ef00aa] |
+| 2026-10-06 | Proposed | Jens Tirsvad Nielsen | S01 | Added RC-006, RC-007 and the source code row | [00d47e2] |
+
+---
+
+## Purpose
+
+Tracks backward/forward links between artifact instances so that the Business Case's
+cross-artifact traceability can be measured. A row is added or updated whenever an
+artifact instance is created or reviewed.
+
+## Traceability Table
+
+| Artifact Instance | Type | Upstream (Backward Link) | Downstream (Forward Link) | Last Reviewed (RC-ID) |
+| --- | --- | --- | --- | --- |
+| [SA-001] | Stakeholder Analysis | - | [BC-001] | [RC-002] |
+| [BC-001] | Business Case | [SA-001] | [PP-001], [MIL-001], [MIL-002], [MIL-003], [MIL-004] | [RC-001] |
+| [PP-001] | Project Plan | [BC-001], [SA-001] | [MIL-001], [MIL-002], [MIL-003], [MIL-004] | - |
+| [MIL-001] | Milestone | [BC-001], [PP-001] | - | [RC-003] |
+| [MIL-002] | Milestone | [BC-001], [PP-001] | - | [RC-004] |
+| [MIL-003] | Milestone | [BC-001], [PP-001] | - | [RC-005] |
+| [MIL-004] | Milestone | [BC-001], [PP-001] | - | [RC-007] |
+| Source code (`src/`, `tests/`) | Source code | [MIL-002], [MIL-003], [MIL-004] | - | [RC-006] |
+
+## Coverage Notes
+
+- `-` in Upstream means foundational; in Downstream, nothing is built on it yet; in Last Reviewed, no `RC-*` exists yet.
+- [PP-001] has no QC checklist in the framework, so it has no `RC-*`.
+- No use case, domain model, design or data artifacts exist; the plan treats all tasks as plain technical tasks. The source code is reviewed in [RC-006].
+
+---
+
+[SA-001]: ../stakeholder-analysis.md
+[BC-001]: ../business-case.md
+[PP-001]: ../project-plan.md
+[MIL-001]: ../milestones/mil-001-project-setup.md
+[MIL-002]: ../milestones/mil-002-coffee-machine-core.md
+[MIL-003]: ../milestones/mil-003-quality-and-publication.md
+[MIL-004]: ../milestones/mil-004-code-review-and-ci.md
+[RC-001]: ./reviews/rc-001-business-case.md
+[RC-002]: ./reviews/rc-002-stakeholder-analysis.md
+[RC-003]: ./reviews/rc-003-mil-001.md
+[RC-004]: ./reviews/rc-004-mil-002.md
+[RC-005]: ./reviews/rc-005-mil-003.md
+[RC-006]: ./reviews/rc-006-source-code.md
+[RC-007]: ./reviews/rc-007-mil-004.md
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d
+[00d47e2]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/00d47e244c82007bbc55e18312649189b175ec10

docs/stakeholder-analysis.md

@@ -9,7 +9,8 @@
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-05 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | [c0c3940] |
+| 2026-10-05 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [c0c3940] |
+| 2026-10-06 | Accepted | Jens Tirsvad Nielsen | S01 | Recorded S01 sign-off after RC-002 | [8ef00aa] |
 
 ---
 
@@ -70,9 +71,10 @@ Monitor).
 
 | Stakeholder | Decision | Date |
 | --- | --- | --- |
-| S01 | Pending review | |
+| S01 | Go (RC-002) | 2026-10-06 |
 
 ---
 
 [BC-001]: ./business-case.md
 [c0c3940]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/c0c3940551db0d7d96492cc734976d0436051ff9
+[8ef00aa]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/015-coffee_machine/commit/8ef00aafaaa193ea565f1a45238d31e963a5e05d

pyproject.toml

@@ -12,7 +12,7 @@ license = { file = "LICENSE" }
 dependencies = []
 
 [project.optional-dependencies]
-dev = ["pytest>=8", "ruff", "mypy"]
+dev = ["pytest>=9", "ruff>=0.16", "mypy>=2.4"]
 
 [project.scripts]
 coffee-machine = "coffee_machine.main:main"
@@ -22,7 +22,7 @@ where = ["src"]
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]
-pythonpath = ["src"]
+pythonpath = ["src", "."]
 
 [tool.ruff]
 line-length = 88

src/coffee_machine/constants.py

@@ -1,6 +1,54 @@
 """!
 @file constants.py
-@brief Constants for the coffee machine: menu, coins and starting resources.
+@brief Constants for the coffee machine: menu, coins, starting resources, texts.
 
-The values are added in MIL-002 ("Define constants").
+Money is stored in whole cents so that sums and change are exact.
 """
+
+from typing import TypedDict
+
+
+class Drink(TypedDict):
+    """!
+    @brief A menu entry: the ingredients it needs and its price.
+    """
+
+    ingredients: dict[str, int]
+    cost: int
+
+
+MENU: dict[str, Drink] = {
+    "espresso": {"ingredients": {"water": 50, "coffee": 18}, "cost": 150},
+    "latte": {
+        "ingredients": {"water": 200, "milk": 150, "coffee": 24},
+        "cost": 250,
+    },
+    "cappuccino": {
+        "ingredients": {"water": 250, "milk": 100, "coffee": 24},
+        "cost": 300,
+    },
+}
+
+## Value of each US coin in cents, in the order the machine asks for them.
+COIN_VALUES: dict[str, int] = {
+    "quarters": 25,
+    "dimes": 10,
+    "nickels": 5,
+    "pennies": 1,
+}
+
+INITIAL_RESOURCES: dict[str, int] = {"water": 300, "milk": 200, "coffee": 100}
+
+## Unit printed after each resource in the report.
+RESOURCE_UNITS: dict[str, str] = {"water": "ml", "milk": "ml", "coffee": "g"}
+
+CENTS_PER_DOLLAR = 100
+
+COMMAND_REPORT = "report"
+COMMAND_OFF = "off"
+
+PROMPT_ORDER = "What would you like? (espresso/latte/cappuccino): "
+MESSAGE_INSERT_COINS = "Please insert coins."
+MESSAGE_NOT_ENOUGH_MONEY = "Sorry that's not enough money. Money refunded."
+MESSAGE_UNKNOWN_DRINK = "Sorry, we do not serve that."
+MESSAGE_INVALID_NUMBER = "Please enter a whole number of coins, zero or more."

src/coffee_machine/main.py

@@ -1,12 +1,138 @@
 """!
 @file main.py
-@brief Entry point of the coffee machine.
+@brief Entry point and logic of the coffee machine.
 """
 
+from coffee_machine.constants import (
+    CENTS_PER_DOLLAR,
+    COIN_VALUES,
+    COMMAND_OFF,
+    COMMAND_REPORT,
+    INITIAL_RESOURCES,
+    MENU,
+    MESSAGE_INSERT_COINS,
+    MESSAGE_INVALID_NUMBER,
+    MESSAGE_NOT_ENOUGH_MONEY,
+    MESSAGE_UNKNOWN_DRINK,
+    PROMPT_ORDER,
+    RESOURCE_UNITS,
+)
+
+
+def format_money(cents: int) -> str:
+    """!
+    @brief Format an amount in cents as dollars.
+    @param cents Amount in whole cents.
+    @return The amount such as "$2.50".
+    """
+    return f"${cents / CENTS_PER_DOLLAR:.2f}"
+
+
+def report(resources: dict[str, int], profit: int) -> None:
+    """!
+    @brief Print the resources left in the machine and the money earned.
+    @param resources Remaining amount of each resource.
+    @param profit Money earned so far, in cents.
+    """
+    for name, amount in resources.items():
+        print(f"{name.capitalize()}: {amount}{RESOURCE_UNITS[name]}")
+    print(f"Money: {format_money(profit)}")
+
+
+def is_resource_sufficient(
+    order_ingredients: dict[str, int], resources: dict[str, int]
+) -> bool:
+    """!
+    @brief Check that the machine has enough of every ingredient for an order.
+    @param order_ingredients Amount of each ingredient the drink needs.
+    @param resources Remaining amount of each resource.
+    @return True if every ingredient is available, otherwise False after
+            printing the first missing one.
+    """
+    for name, needed in order_ingredients.items():
+        if needed > resources[name]:
+            print(f"Sorry there is not enough {name}.")
+            return False
+    return True
+
+
+def _ask_coin_count(coin_name: str) -> int:
+    """!
+    @brief Ask how many coins of one kind are inserted, until the answer is valid.
+    @param coin_name Plural coin name, such as "quarters".
+    @return The number of coins, zero or more.
+    """
+    while True:
+        answer = input(f"How many {coin_name}?: ")
+        try:
+            count = int(answer)
+        except ValueError:
+            count = -1
+        if count >= 0:
+            return count
+        print(MESSAGE_INVALID_NUMBER)
+
+
+def process_coins() -> int:
+    """!
+    @brief Ask for the coins and total their value.
+    @return The total inserted, in cents.
+    """
+    print(MESSAGE_INSERT_COINS)
+    return sum(
+        _ask_coin_count(coin_name) * value for coin_name, value in COIN_VALUES.items()
+    )
+
+
+def is_transaction_successful(money_received: int, drink_cost: int) -> bool:
+    """!
+    @brief Check the payment, refund it if too small, otherwise give change.
+    @param money_received Money inserted, in cents.
+    @param drink_cost Price of the drink, in cents.
+    @return True if the payment covers the price, otherwise False.
+    """
+    if money_received < drink_cost:
+        print(MESSAGE_NOT_ENOUGH_MONEY)
+        return False
+    change = money_received - drink_cost
+    if change > 0:
+        print(f"Here is {format_money(change)} in change.")
+    return True
+
+
+def make_coffee(
+    drink_name: str, order_ingredients: dict[str, int], resources: dict[str, int]
+) -> None:
+    """!
+    @brief Use up the drink's ingredients and serve it.
+    @param drink_name Name of the drink.
+    @param order_ingredients Amount of each ingredient the drink needs.
+    @param resources Remaining amount of each resource; updated in place.
+    """
+    for name, needed in order_ingredients.items():
+        resources[name] -= needed
+    print(f"Here is your {drink_name}. Enjoy!")
+
 
 def main() -> None:
     """!
-    @brief Run the coffee machine.
+    @brief Run the coffee machine until the user types "off".
-
-    The ordering loop is added in MIL-002 ("Implement main loop").
     """
+    resources = dict(INITIAL_RESOURCES)
+    profit = 0
+    while True:
+        choice = input(PROMPT_ORDER).strip().lower()
+        if choice == COMMAND_OFF:
+            return
+        if choice == COMMAND_REPORT:
+            report(resources, profit)
+        elif choice in MENU:
+            drink = MENU[choice]
+            if not is_resource_sufficient(drink["ingredients"], resources):
+                continue
+            payment = process_coins()
+            if is_transaction_successful(payment, drink["cost"]):
+                profit += drink["cost"]
+                make_coffee(choice, drink["ingredients"], resources)
+        else:
+            print(MESSAGE_UNKNOWN_DRINK)

tests/__init__.py

@@ -0,0 +1,4 @@
+"""!
+@file __init__.py
+@brief Test package.
+"""

tests/conftest.py

@@ -0,0 +1,25 @@
+"""!
+@file conftest.py
+@brief Shared pytest helpers.
+"""
+
+from collections.abc import Callable, Iterable
+
+import pytest
+
+ScriptInput = Callable[[Iterable[str]], None]
+
+
+@pytest.fixture
+def script_input(monkeypatch: pytest.MonkeyPatch) -> ScriptInput:
+    """!
+    @brief Provide a function that feeds the given answers to `input`.
+    @param monkeypatch pytest's monkeypatch fixture.
+    @return A function taking the answers in the order they are asked.
+    """
+
+    def feed(answers: Iterable[str]) -> None:
+        remaining = iter(answers)
+        monkeypatch.setattr("builtins.input", lambda _prompt: next(remaining))
+
+    return feed

tests/test_machine.py

@@ -0,0 +1,107 @@
+"""!
+@file test_machine.py
+@brief Tests for making drinks and the main loop.
+"""
+
+import pytest
+
+from coffee_machine.constants import MENU
+from coffee_machine.main import main, make_coffee
+from tests.conftest import ScriptInput
+
+COINS_FOR_LATTE = ["10", "0", "0", "0"]
+NO_COINS = ["0", "0", "0", "0"]
+FULL_REPORT = "Water: 300ml\nMilk: 200ml\nCoffee: 100g\nMoney: $0.00"
+
+
+def test_make_coffee_uses_up_ingredients(capsys: pytest.CaptureFixture[str]) -> None:
+    """!
+    @brief The drink's ingredients are deducted and the drink is served.
+    """
+    resources = {"water": 300, "milk": 200, "coffee": 100}
+    make_coffee("latte", MENU["latte"]["ingredients"], resources)
+    assert resources == {"water": 100, "milk": 50, "coffee": 76}
+    assert capsys.readouterr().out == "Here is your latte. Enjoy!\n"
+
+
+def test_off_ends_the_machine(script_input: ScriptInput) -> None:
+    """!
+    @brief Typing off returns from the loop.
+    """
+    script_input(["off"])
+    main()
+
+
+def test_report_shows_starting_resources(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief A fresh machine reports full resources and no money.
+    """
+    script_input(["report", "off"])
+    main()
+    assert FULL_REPORT in capsys.readouterr().out
+
+
+def test_unknown_input_is_rejected(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief Anything that is not a drink or command prints a message.
+    """
+    script_input(["tea", "off"])
+    main()
+    assert "Sorry, we do not serve that." in capsys.readouterr().out
+
+
+def test_sale_updates_resources_and_profit(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief A paid drink is served, resources drop and profit rises by the price.
+    """
+    script_input(["latte", *COINS_FOR_LATTE, "report", "off"])
+    main()
+    out = capsys.readouterr().out
+    assert "Here is your latte. Enjoy!" in out
+    assert "Water: 100ml\nMilk: 50ml\nCoffee: 76g\nMoney: $2.50" in out
+
+
+def test_refund_changes_nothing(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief An underpaid order is refunded: no drink, no profit.
+    """
+    script_input(["espresso", *NO_COINS, "report", "off"])
+    main()
+    out = capsys.readouterr().out
+    assert "Money refunded." in out
+    assert "Enjoy" not in out
+    assert FULL_REPORT in out
+
+
+def test_overpayment_adds_only_price_to_profit(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief Change is returned and only the price is counted as profit.
+    """
+    script_input(["espresso", "7", "0", "0", "0", "report", "off"])
+    main()
+    out = capsys.readouterr().out
+    assert "Here is $0.25 in change." in out
+    assert "Money: $1.50" in out
+
+
+def test_order_refused_when_resources_run_out(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief After the water is used up, the next order is refused before payment.
+    """
+    script_input(["latte", *COINS_FOR_LATTE, "latte", "off"])
+    main()
+    out = capsys.readouterr().out
+    assert out.count("Please insert coins.") == 1
+    assert "Sorry there is not enough water." in out

tests/test_resources.py

@@ -0,0 +1,52 @@
+"""!
+@file test_resources.py
+@brief Tests for the report and the resource check.
+"""
+
+import pytest
+
+from coffee_machine.constants import INITIAL_RESOURCES, MENU
+from coffee_machine.main import format_money, is_resource_sufficient, report
+
+
+def test_format_money_shows_two_decimals() -> None:
+    """!
+    @brief Cents are shown as dollars with two decimals.
+    """
+    assert format_money(250) == "$2.50"
+    assert format_money(0) == "$0.00"
+
+
+def test_report_prints_resources_and_money(capsys: pytest.CaptureFixture[str]) -> None:
+    """!
+    @brief The report lists each resource with its unit, then the money.
+    """
+    report({"water": 300, "milk": 200, "coffee": 100}, 250)
+    assert capsys.readouterr().out == (
+        "Water: 300ml\nMilk: 200ml\nCoffee: 100g\nMoney: $2.50\n"
+    )
+
+
+def test_is_resource_sufficient_when_enough() -> None:
+    """!
+    @brief An order is accepted when every ingredient is available.
+    """
+    assert is_resource_sufficient(MENU["latte"]["ingredients"], INITIAL_RESOURCES)
+
+
+def test_is_resource_sufficient_when_exactly_enough() -> None:
+    """!
+    @brief Using up an ingredient completely is allowed.
+    """
+    assert is_resource_sufficient({"water": 300}, {"water": 300})
+
+
+def test_is_resource_sufficient_names_missing_resource(
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    """!
+    @brief A short ingredient is refused and named.
+    """
+    resources = {"water": 300, "milk": 100, "coffee": 100}
+    assert not is_resource_sufficient(MENU["latte"]["ingredients"], resources)
+    assert capsys.readouterr().out == "Sorry there is not enough milk.\n"

tests/test_smoke.py

@@ -3,11 +3,14 @@
 @brief Smoke test that the package imports.
 """
 
+import pytest
+
 from coffee_machine import main as main_module
 
 
-def test_main_is_callable() -> None:
+def test_main_is_callable(monkeypatch: pytest.MonkeyPatch) -> None:
     """!
-    @brief The entry point runs without error.
+    @brief The entry point starts and stops on "off".
     """
+    monkeypatch.setattr("builtins.input", lambda _prompt: "off")
     main_module.main()

tests/test_transactions.py

@@ -0,0 +1,56 @@
+"""!
+@file test_transactions.py
+@brief Tests for coin processing and payment.
+"""
+
+import pytest
+
+from coffee_machine.main import is_transaction_successful, process_coins
+from tests.conftest import ScriptInput
+
+
+def test_process_coins_totals_in_cents(script_input: ScriptInput) -> None:
+    """!
+    @brief Quarters, dimes, nickels and pennies add up to the right total.
+    """
+    script_input(["4", "3", "2", "1"])
+    assert process_coins() == 4 * 25 + 3 * 10 + 2 * 5 + 1
+
+
+def test_process_coins_asks_again_on_invalid_count(
+    script_input: ScriptInput, capsys: pytest.CaptureFixture[str]
+) -> None:
+    """!
+    @brief Text and negative counts are rejected and asked again.
+    """
+    script_input(["abc", "-1", "2", "0", "0", "0"])
+    assert process_coins() == 50
+    assert capsys.readouterr().out.count("Please enter a whole number") == 2
+
+
+def test_transaction_refused_when_too_little(
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    """!
+    @brief Too little money is refunded with the refund message.
+    """
+    assert not is_transaction_successful(100, 150)
+    assert "Sorry that's not enough money. Money refunded." in capsys.readouterr().out
+
+
+def test_transaction_accepted_with_exact_payment(
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    """!
+    @brief Exact payment succeeds and gives no change.
+    """
+    assert is_transaction_successful(150, 150)
+    assert "change" not in capsys.readouterr().out
+
+
+def test_transaction_gives_change(capsys: pytest.CaptureFixture[str]) -> None:
+    """!
+    @brief Overpaying succeeds and returns the difference.
+    """
+    assert is_transaction_successful(175, 150)
+    assert capsys.readouterr().out == "Here is $0.25 in change.\n"