Fixes for NPCs and Testing

NPCs and Testing (Sprint 4)

Tickets: #462 (NPC polish and bug fixes), #490 (coverage tests)

Pull requests: #464, #499

In Sprint 4, I focused on polishing the NPC implementation and improving test coverage across several game systems. I fixed NPC dialogue and spawning bugs, corrected NPC positions, and added tests for dialogue, player touch input, and the tutorial UI.

NPC fixes

Spawn positions

I moved two NPCs to improve their placement in the game:

NPC	Change	Reason
Wizard	Moved to the Nether ground floor near the lava	Previously spawned on top of an enemy
Philosopher	Moved to the first platform in Level 2	Previous position was too close to a portal

I updated the relevant map markers in level1-greek.json and level2.json.

Dialogue progression

I fixed several issues in DialogueComponent:

Problem	Fix
Greeting dialogue was skipped	Fixed the dialogue progression so the greeting displays correctly
Quest completion needed an extra key press	The completion result now appears and clears on the same press
Dialogue repeated indefinitely	Fixed the closing behaviour so pressing E can end the conversation

These changes make conversations and quest progression more predictable.

NPC spawning safety

I added a null check in LevelGameArea.spawnNpcs() before accessing the current level. This prevents the method from trying to use a level that has not been loaded.

Shop interaction

The shop-key fix had already been merged into main, so I removed my duplicate implementation and updated ShopkeeperComponentTest to test the existing behaviour.

During manual testing, I verified that H opens the shop and F performs the special attack.

How the dialogue works

The dialogue component handles player interactions with NPCs, progresses through dialogue lines, processes quest interactions and closes the conversation when finished.

The following diagram shows the intended interaction flow:

flowchart TD
    A([Player presses E]) --> B{Dialogue remaining?}
    B -->|Yes| C[Display next line]
    C --> A
    B -->|No| D{Quest interaction?}
    D -->|Yes| E[Process quest interaction]
    E --> F[Display quest result]
    F --> G{Conversation finished?}
    D -->|No| G
    G -->|No| A
    G -->|Yes| H([Close dialogue])

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Testing

I added and extended unit tests to verify the NPC fixes and improve regression coverage across existing game systems.

NPC tests — PR #464

Test class	What it tests
DialogueComponentTest	Dialogue greetings, progression, quest completion and closing conversations
ShopkeeperComponentTest	Shop interaction behaviour
SpinningTextureRenderComponentTest	Spinning texture rendering
LevelGameAreaSpawnNpcsTest	NPC spawning when no level has been loaded
ProvokedComponentTest	NPC provocation behaviour
NpcQuestRegistryTest	NPC quest registry behaviour

Additional tests — PR #499

This PR added 21 test methods (29 test cases) across two new test files and the existing DialogueComponentTest. It changed test files only and did not modify game code.

Test class	What it tests
TouchPlayerInputComponentTest	Movement in all four directions, stopping on key release, diagonal movement, opposite keys cancelling, unrelated keys being ignored, and attacking on touch
TutorialTest	Guide visibility, toggling, fade-in and fade-out, toggling during a fade, and disposal
DialogueComponentTest	Enemy, gold-spending and shield quests, error-state retries, unknown quest types, changing quest parameters, empty dialogue, and dialogue line tracking

These tests cover normal behaviour and edge cases, helping catch regressions when the systems are changed in future.

Testing and validation results

The following checks passed for PR #464 and #499:

• ./gradlew compileJava
• ./gradlew test
• ./gradlew formatCheck

Both PRs passed their GitHub checks, received reviews and were merged into main.

Integration with the existing game

The NPC fixes build on the Sprint 3 implementation rather than replacing it. The updated spawn positions use the existing level maps and NPC spawning system, while the dialogue fixes preserve the existing conversation and quest structure.

The additional tests cover player input, tutorial UI and dialogue behaviour, extending regression coverage across multiple systems that interact with the player.

What changed from the plan

• Shop interaction: I initially implemented the shop-key fix because the shop interaction was conflicting with the special attack key. However, another change had already fixed the issue and was merged into main before my PR was merged. I removed my duplicate implementation and updated ShopkeeperComponentTest to test the existing behaviour instead, avoiding duplicate code.

• NPC spawning safety: While polishing the NPC implementation, I added a null check in LevelGameArea.spawnNpcs() to handle cases where the current level had not been loaded. This also addressed a SonarCloud blocker.

• Test coverage: I expanded the scope of testing beyond the NPC fixes by adding tests for player touch input, tutorial behaviour, and additional dialogue edge cases. This helped improve regression coverage across existing game systems.