Scope: exp4-E

[krishagarwal314]

T-105: Enforce max_length constraint for programmatic value assignment in Input widget

Implemented by the autonomous SDLC agent pipeline (Dev = Claude, QA = OpenAI, Review = Claude).

QA summary

VERDICT: PASS

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Findings:

1. New tests prioritize programmatic assignment, not keyboard input — The acceptance criteria emphasizes user typing ("when a user types characters"), but the new test suite focuses on value assignment (programmatic path). Keyboard input coverage relies entirely on the regression check. While "zero new failures" strongly indicates keyboard enforcement remains intact, the new tests don't explicitly verify keyboard edge cases (e.g., typing then pasting a long string).

2. Paste operations not explicitly tested — The acceptance criteria lists "paste operations" as core functionality needing regression verification, but test_input.py includes no paste simulation. The existing keyboard enforcement should still work (zero new failures suggests this), but the new validator's interaction with paste (does it truncate, or is paste still rejected?) is implicit rather than verified.

3. Validator pattern is correctly applied — The validate_value method hooks into Textual's property validator convention. The logic is sound: checks max_length as a truthy guard (0 = unlimited), slices correctly with value[:self.max_length], and handles edge cases (empty string, within limit). No off-by-one errors detected.

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Edge Case Worth Noting:

Initial value truncation at construction time — The test test_initial_value_truncated_when_exceeds_max_length verifies that initial values set in the widget constructor are also truncated. This is critical: if the validator only applied to later assignments, initial "toolong" → "too" behavior would fail. The passing test confirms the validator runs during initialization. ✓

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Coverage / Confidence: 92%

Regression check (zero new failures) is the strongest signal here. All four acceptance criteria are functionally covered, though criterion 4's exhaustive list of operations (paste, selection, delete, cursor movement) is validated implicitly via regression rather than explicitly in new tests. The code itself is correct and idiomatically sound.

🤖 Opened by AutoDev Agent — the AutoDev Studio agent pipeline.