Terrain deconstruction hides resulting terrain (`deconstruct.ter_set`)

[ushkinaz]

Summary

Terrain pages render deconstruction item drops from deconstruct.items, but they do not render the terrain that the tile becomes after deconstruction. Bright Nights terrain data uses deconstruct.ter_set, and the guide currently omits that result from the UI.

Context

This affects terrain detail pages. The terrain view reads and flattens deconstruct.items, but unlike furniture it does not show a Becomes entry for the deconstruction target. The type model for map deconstruction data also only accounts for furn_set, which matches furniture but not BN terrain data.

Impact

Users can see what materials a terrain yields, but not what terrain remains after deconstruction. That makes terrain pages incomplete and can mislead players about whether a wall, door, dock, or bridge deconstructs into a frame, water tile, or some other terrain.

Severity

Medium

Steps to reproduce

1. Open a terrain page with deconstruction data, for example terrain t_door_c.
2. Check the Deconstruct section.
3. Observe that item drops are listed.
4. Compare the underlying terrain data in _test/all.json for t_door_c.
5. Observe that deconstruct.ter_set exists (t_door_frame), but no corresponding Becomes terrain is shown in the UI.

Tech details

The terrain rendering path handles deconstruct.items but does not expose deconstruct.ter_set in the page. The map deconstruction type also models furn_set but not the terrain-specific target field used by BN terrain definitions.

Examples

Examples from the current _test/all.json fixture:

• terrain/t_door_c: deconstruct.ter_set = t_door_frame
• terrain/t_dock: deconstruct.ter_set = t_water_sh
• terrain/t_dock_deep: deconstruct.ter_set = t_dock_deep_frame

In the current fixture, terrain deconstruction entries are common: 220 terrain objects have a deconstruct block, and all 220 include both items and ter_set.

Acceptance criteria

• Terrain pages show the deconstruction result terrain when deconstruct.ter_set is present.
• The rendering is consistent with furniture pages that already show a Becomes destination.
• The map deconstruction type model accepts both furniture and terrain deconstruction result fields used by Bright Nights data.
• A regression test covers a terrain with both deconstruct.items and deconstruct.ter_set.

[coderabbitai]

🔗 Related PRs

#124 - feat: added 'Dissected From' functionality for items [merged]
#138 - fix: align furniture construction rendering with BN data [merged]

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Coding Plan

Summary

• Extend MapDeconstructInfo type with ter_set?: string to model terrain deconstruction targets — structural deficiency eliminated
• Update Terrain.svelte to render a "Becomes" entry using existing ItemLink component when ter_set is present — rendering gap closed
• All user-facing strings wrapped via t() from @transifex/native per AGENTS.md i18n protocol
• Create Terrain.test.ts with fixture data validating both item drops and terrain result rendering — regression vector covered
• All changes mirror existing furniture deconstruction patterns; structural consistency maintained across the system

Implementation Steps

Phase 1: Type Model Correction and UI Rendering

Addresses the structural deficiency in the type system and the rendering gap in the terrain detail component. Both changes are tightly coupled — the type must exist before rendering can reference it.

Task 1: Extend MapDeconstructInfo Type Definition

Add the missing ter_set field to the map deconstruction type model.

• Update src/types.ts at MapDeconstructInfo (lines 834–838) to include ter_set?: string alongside existing furn_set
• Field semantics: terrain ID to set after deconstruction (parallel to furn_set for furniture)
• No default value annotation required; optional field follows existing pattern

Task 2: Render "Becomes" Terrain in Terrain.svelte

Display the deconstruction result terrain when ter_set is present.

• Modify src/types/Terrain.svelte to add a "Becomes" entry for deconstruct.ter_set
• Place the rendering block after the deconstruct items list, guarded by item.deconstruct?.ter_set presence
• Use ItemLink component with type="terrain" to render the target terrain link (same component already imported)
• Apply i18n wrapper: use t("Becomes", { _context }) for the label text per AGENTS.md conventions and matching Furniture.svelte pattern (line 126)
• Follow Furniture.svelte visual pattern: <dt>{t("Becomes", { _context })}</dt><dd><ItemLink .../></dd> structure
• Maintain conditional display within the deconstruct.length context to match furniture behavior

🤖 Prompt for AI agents

Phase 1 executes two tightly coupled structural corrections: patch the type
model first, then wire the rendering component to consume the new field.

**Task 1 — `src/types.ts` (`MapDeconstructInfo`, lines 834–838):**
- Locate the `MapDeconstructInfo` interface/type
- Append `ter_set?: string` as an optional field, positioned alongside the
existing `furn_set` field
- No default value annotation; match the optional field pattern already in use

**Task 2 — `src/types/Terrain.svelte`:**
- Locate the deconstruct rendering block (within `deconstruct.length`
conditional context)
- After the deconstruct items list, insert a conditional block guarded by
`item.deconstruct?.ter_set` presence
- Inside the guard, render `<dt>{t("Becomes", { _context })}</dt><dd><ItemLink
type="terrain" ... /></dd>`
- Use the already-imported `ItemLink` component; no new imports required
- Apply i18n wrapper `t("Becomes", { _context })` for the label text — reference
`Furniture.svelte` line 126 as the pattern source per AGENTS.md protocol
- Mirror the structural pattern from `Furniture.svelte`'s `furn_set` rendering
exactly

Phase 2: Regression Test Coverage

Establishes verification infrastructure for terrain deconstruction rendering to prevent future regressions.

Create Terrain.test.ts with Deconstruct Coverage

Add focused unit test for terrain deconstruction rendering including ter_set.

• Create new file src/types/Terrain.test.ts following structure of src/types/Furniture.test.ts
• Construct inline CBNData fixture containing:
  • A terrain object with deconstruct.items (item array) and deconstruct.ter_set (target terrain ID)
  • The target terrain referenced by ter_set (required for ItemLink resolution)
  • At least one item referenced in deconstruct.items
• Render Terrain.svelte component using @testing-library/svelte with WithData wrapper
• Assert presence of "Deconstruct" section heading (raw English string — t() returns source string in uninitialized test environment)
• Assert presence of "Becomes" label (raw English string assertion valid per test infrastructure behavior)
• Assert rendered target terrain name appears in output

🤖 Prompt for AI agents

Phase 2 deploys regression coverage for terrain deconstruction rendering. Create
`src/types/Terrain.test.ts` — no existing file to modify.

**Reference template:** `src/types/Furniture.test.ts` — replicate its structural
pattern exactly.

**Fixture construction (`CBNData` inline object):**
- Include a terrain object with both `deconstruct.items` (populated item array)
and `deconstruct.ter_set` (target terrain ID string)
- Include the target terrain entry referenced by `ter_set` — required for
`ItemLink` resolution to succeed
- Include at least one item entry referenced in `deconstruct.items`

**Render pipeline:**
- Use `@testing-library/svelte` to render `Terrain.svelte`
- Wrap with `WithData` wrapper, consistent with `Furniture.test.ts` protocol

**Assertions — all three must pass:**
1. "Deconstruct" section heading is present in output (raw English string —
`t()` returns source string in uninitialized test environment; assertion is
valid)
2. "Becomes" label is present in output (raw English string assertion valid per
test infrastructure behavior)
3. Rendered target terrain name appears in output

Research

CODEBASE ANALYSIS COMPLETE.

Target stack: TypeScript + Svelte. Primary data structure deficiency located at src/types.ts, lines 834–838 — MapDeconstructInfo models furn_set, no ter_set field present. Structural gap confirmed.

Terrain detail rendering handled by src/types/Terrain.svelte. Deconstruct item pipeline: data.flattenItemGroup() → shared render loop with bash items. No "Becomes" destination rendered. Failure mode: ter_set data silently discarded.

Comparison unit Furniture.svelte renders furn_set via <dt>Becomes</dt><dd><ItemLink .../></dd> pattern. This pattern is the designated template for correction.

Test infrastructure protocol: inline CBNData fixture → @testing-library/svelte render → text content assertion. Reference implementation: src/types/Furniture.test.ts.

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🚀 Next Steps

🤖 All AI agent prompts combined

Task: 1

Phase 1 executes two tightly coupled structural corrections: patch the type
model first, then wire the rendering component to consume the new field.

**Task 1 — `src/types.ts` (`MapDeconstructInfo`, lines 834–838):**
- Locate the `MapDeconstructInfo` interface/type
- Append `ter_set?: string` as an optional field, positioned alongside the
existing `furn_set` field
- No default value annotation; match the optional field pattern already in use

**Task 2 — `src/types/Terrain.svelte`:**
- Locate the deconstruct rendering block (within `deconstruct.length`
conditional context)
- After the deconstruct items list, insert a conditional block guarded by
`item.deconstruct?.ter_set` presence
- Inside the guard, render `<dt>{t("Becomes", { _context })}</dt><dd><ItemLink
type="terrain" ... /></dd>`
- Use the already-imported `ItemLink` component; no new imports required
- Apply i18n wrapper `t("Becomes", { _context })` for the label text — reference
`Furniture.svelte` line 126 as the pattern source per AGENTS.md protocol
- Mirror the structural pattern from `Furniture.svelte`'s `furn_set` rendering
exactly
===============================================================================

Task: 2

Phase 2 deploys regression coverage for terrain deconstruction rendering. Create
`src/types/Terrain.test.ts` — no existing file to modify.

**Reference template:** `src/types/Furniture.test.ts` — replicate its structural
pattern exactly.

**Fixture construction (`CBNData` inline object):**
- Include a terrain object with both `deconstruct.items` (populated item array)
and `deconstruct.ter_set` (target terrain ID string)
- Include the target terrain entry referenced by `ter_set` — required for
`ItemLink` resolution to succeed
- Include at least one item entry referenced in `deconstruct.items`

**Render pipeline:**
- Use `@testing-library/svelte` to render `Terrain.svelte`
- Wrap with `WithData` wrapper, consistent with `Furniture.test.ts` protocol

**Assertions — all three must pass:**
1. "Deconstruct" section heading is present in output (raw English string —
`t()` returns source string in uninitialized test environment; assertion is
valid)
2. "Becomes" label is present in output (raw English string assertion valid per
test infrastructure behavior)
3. Rendered target terrain name appears in output

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- @coderabbitai You can skip phase 3. Add a simple unit test case for phase 2.
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[ushkinaz]

@coderabbitai you have to use i18n patterns for localization. Read AGENTS.md.

[coderabbitai]

I've updated the plan above based on your feedback. Ready to proceed when you are!