ci: build from a supplied spec on push, pull request, or call

Author: ariesclark

.github/workflows/build.yaml

@@ -0,0 +1,71 @@
+on:
+  push:
+    branches:
+      - '**'
+  pull_request:
+  workflow_call:
+    inputs:
+      spec-artifact:
+        description: >-
+          Artifact holding the bundled specification. Only reachable when the
+          caller shares this run, so it takes precedence over spec-url.
+        required: false
+        type: string
+        default: ''
+      spec-url:
+        description: Where to download the specification from.
+        required: false
+        type: string
+        default: https://github.com/vrchatapi/specification/releases/latest/download/openapi.json
+      ref:
+        description: Ref of this repository to build.
+        required: false
+        type: string
+        default: main
+
+name: Build
+
+jobs:
+  build:
+    name: javascript
+    runs-on: ubuntu-latest
+    steps:
+      # Named explicitly: when this workflow is called, the context belongs to
+      # the caller, so a bare checkout would fetch the caller's repository.
+      - uses: actions/checkout@v7
+        with:
+          repository: vrchatapi/vrchatapi-javascript
+          ref: ${{ inputs.ref || github.ref }}
+
+      - uses: pnpm/action-setup@v6
+        with:
+          version: 10
+          run_install: false
+
+      - uses: actions/setup-node@v7
+        with:
+          node-version: 24
+          cache: pnpm
+
+      - if: inputs.spec-artifact != ''
+        uses: actions/download-artifact@v8
+        with:
+          name: ${{ inputs.spec-artifact }}
+          path: .
+
+      - if: inputs.spec-artifact == ''
+        run: curl -Lfo openapi.json "${{ inputs.spec-url || 'https://github.com/vrchatapi/specification/releases/latest/download/openapi.json' }}"
+
+      - run: pnpm install
+
+      # `prebuild` regenerates src/generated from ./openapi.json, so this both
+      # generates against the specification and type-checks the result.
+      - run: pnpm build
+
+      - uses: actions/upload-artifact@v7
+        with:
+          name: javascript-${{ github.run_id }}
+          path: |
+            dist
+            src/generated
+          if-no-files-found: ignore