fix: Compile TS to JS during packaging

.github/workflows/ci.yml

@@ -596,6 +596,56 @@ jobs:
       - name: Verify generated types are in sync with schema
         run: npm run schema-typegen-diff-check
 
+  package-resolution:
+    needs: install-and-cibuild
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+      - uses: ./.github/actions/setup-workspace
+
+      - name: Pack the package
+        run: npm pack --pack-destination "$RUNNER_TEMP"
+
+      - name: Install the tarball into a scratch project
+        working-directory: ${{ runner.temp }}
+        run: |
+          mkdir consumer && cd consumer
+          npm init -y
+          npm install "$RUNNER_TEMP"/plotly.js-*.tgz
+
+      - name: Load every compiled module under Node
+        shell: node {0}
+        working-directory: ${{ runner.temp }}/consumer
+        run: |
+          const assert = require('node:assert');
+          const fs = require('node:fs');
+
+          // src/lib/index.js reaches for these before it touches the DOM.
+          globalThis.self = globalThis;
+          globalThis.window = globalThis;
+
+          const paths = [process.cwd()];
+          const load = (name) => require(require.resolve(name, { paths }));
+
+          const modules = fs
+              .globSync('src/**/*.ts', { cwd: process.env.GITHUB_WORKSPACE })
+              .filter((file) => !file.endsWith('.d.ts'))
+              .map((file) => 'plotly.js/' + file.replace(/[.]ts$/, ''));
+
+          if (modules.length === 0) throw new Error('Found no TypeScript sources to check');
+
+          for (const name of modules) load(name);
+
+          const lib = load('plotly.js/src/lib/index');
+
+          assert.strictEqual(lib.mod(-1, 4), 3);
+          assert.strictEqual(lib.modHalf(3, 4), -1);
+          assert.deepStrictEqual(lib.sortObjectKeys({ b: 1, a: 2 }), ['a', 'b']);
+          assert.strictEqual(lib.cleanNumber(' 12 '), 12);
+          assert.strictEqual(typeof lib.counterRegex, 'function');
+
+          console.log('Loaded ' + modules.length + ' compiled modules and src/lib/index.js');
+
   # ============================================================
   # Standalone jobs (no dependencies on install-and-cibuild)
   # ============================================================

.npmignore

@@ -14,3 +14,8 @@ stackgl_modules/node_modules
 tasks
 test
 topojson
+
+# Exclude the TypeScript files (but not declarations) because Node doesn't
+# parse TS when installed in node_modules.
+src/**/*.ts
+!src/**/*.d.ts

draftlogs/8000_fix.md

@@ -0,0 +1 @@
+- Compile TypeScript files under `src/` to JavaScript during packaging to fix Node resolution [[#8000](https://github.com/plotly/plotly.js/pull/8000)]

lib/index.d.ts

@@ -61,12 +61,6 @@ export type {
     YAxisName
 } from '../src/types/core/layout';
 
-// ---------------------------------------------------------------------------
-// Trace data
-// ---------------------------------------------------------------------------
-
-export type { Data } from '../src/types/core/data';
-
 // ---------------------------------------------------------------------------
 // Configuration
 // ---------------------------------------------------------------------------

package.json

@@ -63,7 +63,9 @@
     "preversion": "check-node-version --node 22 --npm 10 && npm-link-check && npm ls --prod --all",
     "version": "npm run build && git add -A lib dist build src/version.js",
     "postversion": "node -e \"console.log('Version bumped and committed. If ok, run: git push && git push --tags')\"",
-    "postpublish": "node tasks/sync_packages.js"
+    "postpublish": "node tasks/sync_packages.js",
+    "prepack": "tsc -b tsconfig.build.json --force",
+    "postpack": "tsc -b tsconfig.build.json --clean"
   },
   "dependencies": {
     "@plotly/d3": "3.8.2",
@@ -73,6 +75,7 @@
     "@turf/area": "^7.3.5",
     "@turf/centroid": "^7.3.5",
     "@turf/meta": "^7.3.5",
+    "@types/d3": "^3.5.53",
     "base64-arraybuffer": "^1.0.2",
     "country-iso-search": "^0.1.2",
     "culori": "^4.0.2",
@@ -111,7 +114,6 @@
     "@biomejs/biome": "^2.5.5",
     "@plotly/mathjax-v3": "npm:mathjax@^3.2.2",
     "@plotly/mathjax-v4": "npm:mathjax@^4.1.3",
-    "@types/d3": "3.5.34",
     "@types/node": "^26.1.1",
     "assert": "^2.1.0",
     "buffer": "^6.0.3",

src/types/core/data.internal.d.ts

@@ -2,11 +2,11 @@
  * Internal data/trace types (not in public API)
  *
  * These are runtime-resolved versions of trace data with internal state
- * properties. For public trace types, see data.d.ts.
+ * properties. For public trace types, see generated/schema.d.ts.
  */
 
+import type { Data } from '../generated/schema';
 import type { Datum } from '../lib/common';
-import type { Data } from './data';
 
 /**
  * Calculated trace data (internal).

tsconfig.build.json

@@ -0,0 +1,30 @@
+{
+  // Emit configuration for the published package.
+  //
+  // The repository authors a growing share of `src/` in TypeScript, but the
+  // published package must contain only JavaScript. Node's CommonJS resolver
+  // never tries a `.ts` extension, and Node refuses to strip types from any
+  // file below `node_modules`. So the `prepack` script writes a `.js` sibling
+  // for each `.ts` source, and `postpack` deletes it again.
+  //
+  // No `outDir` is set, so each `.js` lands next to its `.ts`. That is what
+  // makes `require('./mod')` resolve in the tarball.
+  //
+  // Build mode drives both scripts. `tsc -b` emits, and `tsc -b --clean`
+  // removes every generated file. Build mode also writes a state file, which
+  // `tsBuildInfoFile` parks below `build/`, because `build/` is already
+  // ignored by both git and npm.
+  //
+  // Type errors are not reported here. `npm run typecheck` owns that job and
+  // reads the whole program, including the JavaScript files.
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "noEmit": false,
+    "noCheck": true,
+    "allowJs": false,
+    "module": "commonjs",
+    "tsBuildInfoFile": "build/tsconfig.build.tsbuildinfo"
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["src/types/**"]
+}