test(fig): pin override and variable precedence to what Figma renders (#912)

* test(fig): pin override and variable precedence to what Figma renders

The rule that decides between a bound variable and an instance's text
override is not stated anywhere we control: an owner's consumption
entry binds the field when it carries variableData and clears it when
it is bare, and a binding beats a literal an outer owner recorded.

The archive is a six-node file authored in Figma for exactly these
cases, so the expected strings are Figma's own output rather than ours.
It replaces reaching for a 44k-record community file to check this.

* ci: pull the new fixture in the quick unit shards

The quick shards fetch an explicit list of small LFS fixtures, so a new
one arrives as a pointer and the fig shard fails parsing it.

.github/workflows/ci.yml

@@ -243,7 +243,7 @@ jobs:
         with:
           lfs: 'true'
           # Quick shards read only the small fixtures; heavy-tests.yml pulls the large .fig corpora.
-          lfs-include: tests/fixtures/gold-preview.fig,tests/fixtures/circle-text.fig,tests/fixtures/slots.fig,tests/fixtures/fonts/*
+          lfs-include: tests/fixtures/gold-preview.fig,tests/fixtures/circle-text.fig,tests/fixtures/slots.fig,tests/fixtures/variable-override-precedence.fig,tests/fixtures/fonts/*
 
       - name: Build shared Core test dependency
         run: bun --filter @open-pencil/core build

packages/fig/tests/document/variable-override-precedence.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, test } from 'bun:test'
+
+import { readFixtureArrayBuffer } from '#fig-tests/helpers/fig-fixtures'
+
+import { materializeFigArchive } from '@open-pencil/fig'
+import type { SceneGraph, SceneNode } from '@open-pencil/scene-graph'
+
+/**
+ * An override and a variable binding can both state a text node's content, and which one Figma
+ * shows is decided by the owner's consumption entry: an entry carrying `variableData` binds the
+ * field, a bare entry clears it. The archive was authored in Figma for these four cases and the
+ * expected strings are what Figma itself renders for them, so this pins our reading to that.
+ */
+const FIGMA_RENDERS: Record<string, string> = {
+  // The component re-binds the field, so the binding wins over the literal each instance records.
+  'same-literal': 'Button-sm',
+  'different-literal': 'Button-sm',
+  // Its literal override is stale — the field was rebound after the override was recorded.
+  'return-to-inherited': 'Button-sm',
+  // Its owner's entry is bare, which clears the binding, so the literal shows.
+  staged: 'Learn more'
+}
+
+function firstText(graph: SceneGraph, instance: SceneNode): string | undefined {
+  const stack = [...instance.childIds]
+  while (stack.length > 0) {
+    const node = graph.getNode(stack.pop() as string)
+    if (!node) continue
+    if (node.type === 'TEXT') return node.text
+    stack.push(...node.childIds)
+  }
+  return undefined
+}
+
+describe('variable binding against an instance override', () => {
+  test('resolves each authored case the way Figma renders it', () => {
+    const { graph } = materializeFigArchive(
+      readFixtureArrayBuffer('variable-override-precedence.fig')
+    )
+    const instances = [...graph.getAllNodes()].filter((node) => node.type === 'INSTANCE')
+    const rendered: Record<string, string | undefined> = {}
+    for (const name of Object.keys(FIGMA_RENDERS)) {
+      const instance = instances.find((node) => node.name === name)
+      expect(instance, `missing instance ${name}`).toBeDefined()
+      rendered[name] = instance ? firstText(graph, instance) : undefined
+    }
+
+    expect(rendered).toEqual(FIGMA_RENDERS)
+  })
+})

tests/fixtures/variable-override-precedence.fig

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:636796f9c78161e084ebd972b5a7d78a7d7c5211e48047e576249946d3237e78
+size 41243