Add the console game loop and entry point

Add show_round, ask_choice and play_game with injectable input and output, and make python -m higher_lower play a game. Each account is shown once per game; a wrong guess or running out of accounts ends it. Invalid input is re-asked. Ctrl+C and Ctrl+D leave with a goodbye. Cover the loop with scripted tests (36 passing). Task: MIL-003#1 Task: MIL-003#2 Task: MIL-003#3 Task: MIL-003#4 Task: MIL-003#5 Closes #12 Closes #13 Closes #14 Closes #15 Closes #16
Accept UCD-001, US-001, UC-001 and SSD-001 after review
2026-10-04 23:49:09 +08:00 · 2026-10-04 23:48:42 +08:00
15 changed files with 495 additions and 22 deletions
@@ -15,7 +15,7 @@ document of a type. `Primary File` may contain a glob (e.g.
 | SA | Stakeholder Analysis | docs/stakeholder-analysis.md | 002 |
 | PP | Project Plan | docs/project-plan.md | 002 |
 | MIL | Milestone / Gateway | docs/milestones/*.md | 005 |
-| RC | SQA Review Record | docs/sqa/reviews/rc-*.md | 007 |
+| RC | SQA Review Record | docs/sqa/reviews/rc-*.md | 011 |
 | TM | Traceability Matrix | docs/sqa/traceability-matrix.md | 002 |
 | UCD | Use Case Diagram | docs/use-case-diagram.md | 002 |
 | US | User Story | docs/user-stories.md | 002 |
@@ -0,0 +1,47 @@
 # SQA Review Record: UCD-001 Use Case Diagram
 ## Metadata
 | Key | Value |
 | --- | --- |
 | ID | RC-007 |
 | CrossReference | [UCD-001], [QC-UCD-001] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | pending |
 ---
 ## Artifact Under Review
 - Instance reviewed: [UCD-001]
 - Checklist used: [QC-UCD-001]
 ## Checklist Results
 | # | Criterion | Status | Evidence/Notes |
 | --- | --- | --- | --- |
 | 1 | Actors are defined with correct UML stereotypes (e.g. `<<System>>`, `<<Actor>>`) | Pass | Actor <<Actor>> and boundary <<System>> stereotyped. |
 | 2 | System boundary is clearly drawn and labeled | Pass | Boundary rectangle labelled Higher Lower. |
 | 3 | Include/extend relationships are used correctly per UML 2.5.1, not as generic "uses" arrows | Pass | No include/extend used; the Relationships section says so. |
 | 4 | Every actor participates in at least one use case (no orphan actors) | Pass | Player is in Play a Game. |
 | 5 | Diagram is traceable to a documented stakeholder need | Pass | Player traces to S01 and S02 in SA-001. |
 | 6 | Use case names are verb phrases describing actor goals, not internal system operations | Pass | Play a Game is an actor goal. |
 | 7 | Diagram is free of implementation detail (e.g. UI widgets, database tables) (Optional) | Pass | No UI or storage detail. |
 | 8 | Actor and use case naming is consistent with corresponding Use Case and User Story documents (Optional) | Pass | Names match US-001 and UC-001. |
 ## Overall Verdict
 Go — all applicable criteria pass. Reviewer and author are both S01: the project has a single participant, so the framework's author/reviewer separation cannot be met. S01 accepted this deviation when requesting acceptance (2026-10-04).
 ## Action Items
 | Action | Owner | Due |
 | --- | --- | --- |
 | None | — | — |
 ---
 [UCD-001]: ../../use-case-diagram.md
 [QC-UCD-001]: ../../../framework/qc/qc-use-case-diagram.md
@@ -0,0 +1,46 @@
 # SQA Review Record: US-001 User Stories
 ## Metadata
 | Key | Value |
 | --- | --- |
 | ID | RC-008 |
 | CrossReference | [US-001], [QC-US-001] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | pending |
 ---
 ## Artifact Under Review
 - Instance reviewed: [US-001]
 - Checklist used: [QC-US-001]
 ## Checklist Results
 | # | Criterion | Status | Evidence/Notes |
 | --- | --- | --- | --- |
 | 1 | Follows INVEST criteria (Independent, Negotiable, Valuable, Estimable, Small, Testable) | Pass | INVEST check present, no exceptions. |
 | 2 | Written in "As a / I want / So that" form | Pass | Both stories use As a / I want / so that. |
 | 3 | Clear, testable acceptance criteria are included | Pass | Given/When/Then criteria on both stories. |
 | 4 | Traceable to a use case or epic | Pass | Both trace to UC-001 and MIL-003. |
 | 5 | Story is sized to fit within a single iteration (Optional) | Pass | Each fits one iteration. |
 | 6 | Story statement avoids technical implementation detail (Optional) | Pass | Stated as player goals. |
 | 7 | Role named in the story matches an actor defined in the Use Case Diagram | Pass | Role Player matches UCD-001. |
 ## Overall Verdict
 Go — all applicable criteria pass. Reviewer and author are both S01: the project has a single participant, so the framework's author/reviewer separation cannot be met. S01 accepted this deviation when requesting acceptance (2026-10-04).
 ## Action Items
 | Action | Owner | Due |
 | --- | --- | --- |
 | None | — | — |
 ---
 [US-001]: ../../user-stories.md
 [QC-US-001]: ../../../framework/qc/qc-user-story.md
@@ -0,0 +1,51 @@
 # SQA Review Record: UC-001 Use Case
 ## Metadata
 | Key | Value |
 | --- | --- |
 | ID | RC-009 |
 | CrossReference | [UC-001], [QC-UC-001] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | pending |
 ---
 ## Artifact Under Review
 - Instance reviewed: [UC-001]
 - Checklist used: [QC-UC-001]
 ## Checklist Results
 | # | Criterion | Status | Evidence/Notes |
 | --- | --- | --- | --- |
 | 1 | Consists of a single, concise paragraph summarizing only the primary success scenario | N-A | Applies to the Brief format only; this use case is Fully Dressed. |
 | 2 | Written as an informal multi-paragraph narrative; may mention some alternate flows without formal structure | N-A | Applies to the Casual format only; this use case is Fully Dressed. |
 | 3 | All standard sections are present: actors, preconditions, postconditions, main success scenario, alternative/exception flows | Pass | Scope, level, actor, stakeholders, pre/postconditions, scenario, extensions, rules and open issues present. |
 | 4 | Preconditions and postconditions are explicitly defined | Pass | Both defined. |
 | 5 | Primary actor is explicitly stated | Pass | Player. |
 | 6 | Stakeholders and their interests are stated | Pass | S01 and S02 with interests. |
 | 7 | Main success scenario is written as clear, numbered steps | Pass | Seven numbered steps. |
 | 8 | Alternative/exception flows correctly reference `<<include>>`/`<<extend>>` use cases where relevant, per UML 2.5.1 | Pass | No include/extend applies; stated. |
 | 9 | Explicit business rules are captured per step where applicable, rather than embedded loosely in narrative text (Optional) | Pass | Rules listed for steps 2, 3b and 5. |
 | 10 | Naming of actors and use case title is consistent with the corresponding Use Case Diagram and User Stories | Pass | Title and actor match UCD-001 and US-001. |
 | 11 | Scope/level (e.g. summary, user-goal, subfunction) is explicitly stated (Optional) | Pass | Level: user goal. |
 | 12 | Use case is written from the actor's goal perspective, free of UI or implementation detail | Pass | Goal wording, no UI or implementation detail. |
 ## Overall Verdict
 Go — all applicable criteria pass. Reviewer and author are both S01: the project has a single participant, so the framework's author/reviewer separation cannot be met. S01 accepted this deviation when requesting acceptance (2026-10-04).
 ## Action Items
 | Action | Owner | Due |
 | --- | --- | --- |
 | None | — | — |
 ---
 [UC-001]: ../../uc-001/uc.md
 [QC-UC-001]: ../../../framework/qc/qc-use-case.md
@@ -0,0 +1,46 @@
 # SQA Review Record: SSD-001 System Sequence Diagram
 ## Metadata
 | Key | Value |
 | --- | --- |
 | ID | RC-010 |
 | CrossReference | [SSD-001], [QC-SSD-001] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Initial version | pending |
 ---
 ## Artifact Under Review
 - Instance reviewed: [SSD-001]
 - Checklist used: [QC-SSD-001]
 ## Checklist Results
 | # | Criterion | Status | Evidence/Notes |
 | --- | --- | --- | --- |
 | 1 | Input/output messages match the corresponding Use Case's main success scenario step-for-step | Pass | startGame and makeGuess cover steps 1 to 7 of UC-001. |
 | 2 | Actor and System are treated strictly as black boxes (system shown as `:System`) | Pass | Only Player and :System. |
 | 3 | Object creation/destruction of the System instance handled explicitly where relevant (Optional) | Pass | Lifecycle notes state when the game starts and ends. |
 | 4 | Return values are shown for operations that produce one, using dashed return arrows | Pass | Dashed returns on every operation. |
 | 5 | Alternate/exceptional flows are represented separately (or explicitly out of scope noted) | Pass | Alternative flows noted as out of scope. |
 | 6 | Message names are verb phrases consistent with the use case's system responsibilities (Optional) | Pass | startGame, makeGuess. |
 | 7 | Diagram references the specific Use Case (name and ID) it depicts | Pass | Cites UC-001 Play a Game. |
 ## Overall Verdict
 Go — all applicable criteria pass. Reviewer and author are both S01: the project has a single participant, so the framework's author/reviewer separation cannot be met. S01 accepted this deviation when requesting acceptance (2026-10-04).
 ## Action Items
 | Action | Owner | Due |
 | --- | --- | --- |
 | None | — | — |
 ---
 [SSD-001]: ../../uc-001/ssd.md
 [QC-SSD-001]: ../../../framework/qc/qc-ssd.md
@@ -9,8 +9,8 @@
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
 | 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Added RC-005 review of MIL-002 | [ee58fcd] |
 | 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Added RC-006 and the UC-001 artifacts | [923dde7] |
 | 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Added RC-007 to RC-010 for UCD-001, US-001, UC-001 and SSD-001 | pending |
 ---
@@ -30,14 +30,14 @@ target is measurable. A row is added or updated whenever an artifact instance is
 | [MIL-002] | MIL | [BC-001], [PP-001], [MIL-001] | - | [RC-005] |
 | [MIL-003] | MIL | [BC-001], [PP-001], [MIL-002], [US-001] | [UC-001] | [RC-006] |
 | [MIL-004] | MIL | [BC-001], [PP-001] | - | - |
-| [UCD-001] | UCD | [SA-001], [BC-001] | [US-001], [UC-001] | - |
+| [UCD-001] | UCD | [SA-001], [BC-001] | [US-001], [UC-001] | [RC-007] |
-| [US-001] | US | [UCD-001], [BC-001], [MIL-003] | [UC-001] | - |
+| [US-001] | US | [UCD-001], [BC-001], [MIL-003] | [UC-001] | [RC-008] |
-| [UC-001] | UC | [UCD-001], [US-001], [SA-001] | [SSD-001] | - |
+| [UC-001] | UC | [UCD-001], [US-001], [SA-001] | [SSD-001] | [RC-009] |
-| [SSD-001] | SSD | [UC-001] | - | - |
+| [SSD-001] | SSD | [UC-001] | - | [RC-010] |
 ## Coverage Notes
- UCD-001, US-001, UC-001 and SSD-001 exist but are not reviewed yet. No domain model or design artifacts exist yet.
+- No domain model or design artifacts exist yet.
 - `-` in Upstream means foundational; in Downstream, nothing is built on it yet; in Last Reviewed, no `RC-*` exists yet.
 ---
@@ -54,10 +54,13 @@ target is measurable. A row is added or updated whenever an artifact instance is
 [RC-003]: ./reviews/rc-003-project-plan.md
 [RC-004]: ./reviews/rc-004-mil-001.md
 [RC-005]: ./reviews/rc-005-mil-002.md
 [ee58fcd]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/ee58fcdc1c9c83b0721022d623e4989591a47987
 [UCD-001]: ../use-case-diagram.md
 [US-001]: ../user-stories.md
 [UC-001]: ../uc-001/uc.md
 [SSD-001]: ../uc-001/ssd.md
 [RC-006]: ./reviews/rc-006-mil-003.md
 [923dde7]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/923dde7dc9b59d2c77eddc88336451193147c557
 [RC-007]: ./reviews/rc-007-ucd-001.md
 [RC-008]: ./reviews/rc-008-us-001.md
 [RC-009]: ./reviews/rc-009-uc-001.md
 [RC-010]: ./reviews/rc-010-ssd-001.md
@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | SSD-001 |
-| CrossReference | [UC-001] |
+| CrossReference | [UC-001], [RC-010] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
+| 2026-10-04 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Accepted after review RC-010 | pending |
 ---
@@ -52,3 +53,4 @@ A game starts with `startGame` and ends when `makeGuess` returns wrong; the Syst
 [UC-001]: ./uc.md
 [923dde7]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/923dde7dc9b59d2c77eddc88336451193147c557
 [RC-010]: ../sqa/reviews/rc-010-ssd-001.md
@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | UC-001 |
-| CrossReference | [UCD-001], [US-001], [SA-001], [SSD-001] |
+| CrossReference | [UCD-001], [US-001], [SA-001], [SSD-001], [RC-009] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
+| 2026-10-04 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Accepted after review RC-009 | pending |
 ---
@@ -76,3 +77,4 @@ None.
 [SA-001]: ../stakeholder-analysis.md
 [SSD-001]: ./ssd.md
 [923dde7]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/923dde7dc9b59d2c77eddc88336451193147c557
 [RC-009]: ../sqa/reviews/rc-009-uc-001.md
@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | UCD-001 |
-| CrossReference | [SA-001], [BC-001], [US-001], [UC-001] |
+| CrossReference | [SA-001], [BC-001], [US-001], [UC-001], [RC-007] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
+| 2026-10-04 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Accepted after review RC-007 | pending |
 ---
@@ -53,3 +54,4 @@ None: there is a single use case, so no `<<include>>` or `<<extend>>` is used.
 [US-001]: ./user-stories.md
 [UC-001]: ./uc-001/uc.md
 [923dde7]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/923dde7dc9b59d2c77eddc88336451193147c557
 [RC-007]: ./sqa/reviews/rc-007-ucd-001.md
@@ -4,12 +4,13 @@
 | Key | Value |
 | --- | --- |
 | ID | US-001 |
-| CrossReference | [UCD-001], [UC-001], [BC-001], [MIL-003] |
+| CrossReference | [UCD-001], [UC-001], [BC-001], [MIL-003], [RC-008] |
 ## Version History
 | Date | Status | Author | Reviewer | Change | Commit |
 | --- | --- | --- | --- | --- | --- |
-| 2026-10-04 | Proposed | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
+| 2026-10-04 | Deprecated | Jens Tirsvad Nielsen | S01 | Initial version | [923dde7] |
 | 2026-10-04 | Accepted | Jens Tirsvad Nielsen | S01 | Accepted after review RC-008 | pending |
 ---
@@ -49,3 +50,4 @@ Both stories are Independent of each other in wording, Negotiable in detail, Val
 [BC-001]: ./business-case.md
 [MIL-003]: ./milestones/mil-003-console-game.md
 [923dde7]: https://git.tirsystem.com/Tirsvad-Udemy-100_days_of_code/014-higher_lower/commit/923dde7dc9b59d2c77eddc88336451193147c557
 [RC-008]: ./sqa/reviews/rc-008-us-001.md
@@ -2,12 +2,17 @@
@brief Entry point for `python -m higher_lower`.
 """
 from higher_lower.constants import MSG_GOODBYE
 from higher_lower.game import play_game
 def main() -> None:
-    """@brief Start the game.
+    """@brief Play a game; leave quietly if the player quits with Ctrl+C or Ctrl+D."""
-
+    try:
-    Placeholder: the game loop is implemented in MIL-003.
+        play_game()
-    """
+    except (EOFError, KeyboardInterrupt):
        print()
        print(MSG_GOODBYE)
 if __name__ == "__main__":
@@ -26,3 +26,4 @@ MSG_INVALID_CHOICE = "Please type 'A' or 'B'."
 MSG_CORRECT = "You're right! Current score: {score}."
 MSG_WRONG = "Sorry, that's wrong. Final score: {score}"
 MSG_WIN = "You went through every account! Final score: {score}"
 MSG_GOODBYE = "Goodbye!"
@@ -0,0 +1,122 @@
 """@file game.py
@brief The interactive game: what the player sees, what they type, and the game loop.
 Input and output go through callables so tests can script a whole game.
 """
 import random
 from collections.abc import Callable, Sequence
 from higher_lower.art import logo, vs
 from higher_lower.constants import (
    CHOICE_A,
    CHOICE_B,
    KEY_FOLLOWER_COUNT,
    KEY_NAME,
    MSG_AGAINST_B,
    MSG_COMPARE_A,
    MSG_CORRECT,
    MSG_INVALID_CHOICE,
    MSG_WIN,
    MSG_WRONG,
    PROMPT_GUESS,
    START_SCORE,
 )
 from higher_lower.game_data import Account, data
 from higher_lower.game_logic import (
    check_answer,
    format_data,
    get_random_account,
    pick_pair,
 )
 InputFunc = Callable[[str], str]
 OutputFunc = Callable[[str], None]
 def show_round(
    account_a: Account,
    account_b: Account,
    output: OutputFunc = print,
 ) -> None:
    """@brief Show the two accounts the player compares.
    @param account_a The account shown as A.
    @param account_b The account shown as B.
    @param output Where the text goes.
    """
    output(MSG_COMPARE_A.format(account=format_data(account_a)))
    output(vs)
    output(MSG_AGAINST_B.format(account=format_data(account_b)))
 def ask_choice(input_func: InputFunc = input, output: OutputFunc = print) -> str:
    """@brief Ask for A or B until the player gives a valid answer.
    @param input_func Reads one line of input, given the prompt.
    @param output Where the invalid-answer message goes.
    @return "a" or "b", in lower case.
    """
    while True:
        answer = input_func(PROMPT_GUESS).strip().lower()
        if answer in (CHOICE_A, CHOICE_B):
            return answer
        output(MSG_INVALID_CHOICE)
 def _pick_next_account(
    accounts: Sequence[Account],
    shown_names: set[str],
    rng: random.Random | None,
 ) -> Account | None:
    """@brief Draw an account that has not been shown in this game.
    @param accounts All accounts of the game.
    @param shown_names Names of the accounts already shown.
    @param rng Random generator, or None for the default.
    @return A new account, or None if every account has been shown.
    """
    unused = [account for account in accounts if account[KEY_NAME] not in shown_names]
    if not unused:
        return None
    return get_random_account(unused, rng)
 def play_game(
    accounts: Sequence[Account] = data,
    rng: random.Random | None = None,
    input_func: InputFunc = input,
    output: OutputFunc = print,
 ) -> int:
    """@brief Play one game, from the logo to the final score.
    Each account is shown once per game. A right guess adds a point and
    makes B the next A; a wrong guess, or running out of accounts, ends
    the game.
    @param accounts The accounts to play with; needs at least two entries.
    @param rng Random generator; pass a seeded one for a repeatable game.
    @param input_func Reads one line of input, given the prompt.
    @param output Where the text goes.
    @return The final score.
    """
    output(logo)
    score = START_SCORE
    account_a, account_b = pick_pair(accounts, rng)
    shown_names = {account_a[KEY_NAME], account_b[KEY_NAME]}
    while True:
        show_round(account_a, account_b, output)
        guess = ask_choice(input_func, output)
        if not check_answer(
            guess, account_a[KEY_FOLLOWER_COUNT], account_b[KEY_FOLLOWER_COUNT]
        ):
            output(MSG_WRONG.format(score=score))
            return score
        score += 1
        output(MSG_CORRECT.format(score=score))
        next_account = _pick_next_account(accounts, shown_names, rng)
        if next_account is None:
            output(MSG_WIN.format(score=score))
            return score
        account_a, account_b = account_b, next_account
        shown_names.add(next_account[KEY_NAME])
@@ -0,0 +1,144 @@
 """@file test_game.py
@brief Tests for the game loop, run with scripted input and no real console.
 """
 import io
 import random
 from collections.abc import Callable, Iterable, Sequence
 import pytest
 from higher_lower import __main__ as entry_point
 from higher_lower.art import logo
 from higher_lower.game import ask_choice, play_game, show_round
 from higher_lower.game_data import Account
 ACCOUNTS: list[Account] = [
    {"name": "First", "follower_count": 30, "description": "Test one", "country": "Denmark"},
    {"name": "Second", "follower_count": 20, "description": "Test two", "country": "Norway"},
    {"name": "Third", "follower_count": 10, "description": "Test three", "country": "Sweden"},
 ]
 class FirstRng(random.Random):
    """@brief Random generator that always takes the first entries, so a game is fixed."""
    def sample(self, population: Sequence, k: int, **kwargs: object) -> list:  # type: ignore[override]
        """@brief Return the first k entries."""
        return list(population)[:k]
    def choice(self, seq: Sequence) -> Account:  # type: ignore[override]
        """@brief Return the first entry."""
        return seq[0]
 def scripted(answers: Iterable[str]) -> Callable[[str], str]:
    """@brief Make an input function that gives the answers one by one.
    @param answers The answers to give.
    @return A function with the signature of input().
    """
    iterator = iter(answers)
    return lambda _prompt: next(iterator)
 def run_game(answers: Iterable[str]) -> tuple[int, str]:
    """@brief Play a fixed game and return the score and everything shown.
    @param answers The answers the player gives.
    @return The final score and the output joined with newlines.
    """
    lines: list[str] = []
    score = play_game(ACCOUNTS, FirstRng(), scripted(answers), lines.append)
    return score, "\n".join(lines)
 def test_show_round_shows_both_accounts() -> None:
    """@brief Both accounts are described, with the vs art between them."""
    lines: list[str] = []
    show_round(ACCOUNTS[0], ACCOUNTS[1], lines.append)
    assert lines[0] == "Compare A: First, a Test one, from Denmark."
    assert lines[2] == "Against B: Second, a Test two, from Norway."
@pytest.mark.parametrize("typed", ["a", "A", " a "])
 def test_ask_choice_accepts_a(typed: str) -> None:
    """@brief A is accepted in any case and with spaces around it."""
    assert ask_choice(scripted([typed]), lambda _line: None) == "a"
 def test_ask_choice_asks_again_after_an_invalid_answer() -> None:
    """@brief Invalid answers are rejected and the player is asked again."""
    lines: list[str] = []
    assert ask_choice(scripted(["x", "", "b"]), lines.append) == "b"
    assert len(lines) == 2
 def test_correct_streak_adds_a_point_per_round() -> None:
    """@brief Each right guess adds one to the score and B becomes the next A."""
    score, shown = run_game(["a", "a"])
    assert score == 2
    assert "Current score: 1." in shown
    assert "Compare A: Second" in shown
 def test_wrong_first_guess_ends_the_game_with_zero() -> None:
    """@brief A wrong guess ends the game and shows the final score."""
    score, shown = run_game(["b"])
    assert score == 0
    assert "Sorry, that's wrong. Final score: 0" in shown
 def test_wrong_guess_after_a_point_keeps_the_score() -> None:
    """@brief The final score is the number of right guesses."""
    score, shown = run_game(["a", "b"])
    assert score == 1
    assert "Final score: 1" in shown
 def test_invalid_input_does_not_change_the_round() -> None:
    """@brief An invalid answer is re-asked without ending the game or scoring."""
    score, shown = run_game(["x", "a", "a"])
    assert score == 2
    assert shown.count("Compare A: First") == 1
 def test_game_ends_with_a_win_when_the_accounts_run_out() -> None:
    """@brief Using every account ends the game instead of failing."""
    score, shown = run_game(["a", "a"])
    assert score == 2
    assert "You went through every account!" in shown
 def test_game_starts_with_the_logo() -> None:
    """@brief The logo is shown first."""
    _score, shown = run_game(["b"])
    assert shown.startswith(logo)
 def test_full_game_with_the_assignment_data_ends() -> None:
    """@brief A game with the real data set ends with a final score."""
    lines: list[str] = []
    score = play_game(
        rng=random.Random(5), input_func=lambda _prompt: "a", output=lines.append
    )
    assert score >= 0
    assert "Final score" in lines[-1]
 def test_main_plays_a_game(
    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
 ) -> None:
    """@brief main() runs a game on the console."""
    monkeypatch.setattr("sys.stdin", io.StringIO("a\n" * 100))
    entry_point.main()
    assert "Final score" in capsys.readouterr().out
 def test_main_leaves_quietly_on_end_of_input(
    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
 ) -> None:
    """@brief Ctrl+D ends the game with a goodbye, not a traceback."""
    monkeypatch.setattr("sys.stdin", io.StringIO(""))
    entry_point.main()
    assert "Goodbye!" in capsys.readouterr().out
@@ -12,5 +12,5 @@ def test_package_imports() -> None:
 def test_entry_point_is_callable() -> None:
-    """@brief The entry point exists and can be called."""
+    """@brief The entry point exists; importing it does not start a game."""
-    assert entry_point.main() is None
+    assert callable(entry_point.main)