fix(ci): classify images/fonts/binaries as inert instead of production in revert-oracle (#4140)

An image, font, or archive has no observable behaviour: no runner in this
repo compiles or executes one, so a test can neither accompany nor observe
a change to it. classifyPath put such files in `production` by default,
so the oracle ABORTed with "changes production code and adds/changes NO
test file" on branches whose only changes were of this kind — e.g. five
deleted favicon PNGs, or an archive of retained evidence files. That is a
false positive about the classifier, not a finding about the branch.

Add a narrow `inert` classification (images, fonts, a few other binary
container formats) alongside the existing `production`/`test`/`ignored`
kinds, extracted to scripts/lib/revert-oracle-inert.mjs to stay under the
module-size budget. `.json` and other formats a runner's behaviour can
depend on are deliberately excluded, so a source file with no test still
ABORTs exactly as before.

Closes #4137

Co-authored-by: Louis Trümpler <78563314+louistrue@users.noreply.github.com>

Author: BIMvoice

scripts/check-test-revert-oracle.mjs

@@ -263,7 +263,7 @@ if (opts.ci && isDependabotDependencyOnly(process.env.PR_AUTHOR_LOGIN, entries))
   process.exit(0);
 }
 
-const { production, test: testEntries, ignored, warnings } = classifyDiff(entries);
+const { production, test: testEntries, ignored, inert, warnings } = classifyDiff(entries);
 for (const w of warnings) console.log(`  WARNING: ${w}`);
 
 let prodPaths = production.map((e) => e.path);
@@ -280,7 +280,9 @@ if (opts.tests.length > 0) {
   if (testPaths.length === 0) die(EXIT_NOTHING_CHECKED, '--test matched none of the branch\'s changed test files.');
 }
 
-console.log(`  files: ${production.length} production, ${testEntries.length} test, ${ignored.length} ignored`);
+console.log(
+  `  files: ${production.length} production, ${testEntries.length} test, ${ignored.length} ignored, ${inert.length} inert`,
+);
 
 if (prodPaths.length === 0) {
   const message = 'this branch changes no production files; there is nothing whose absence a test could notice.';

scripts/lib/revert-oracle-inert.mjs

@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/**
+ * File kinds no runner in this repo (vitest, node --test, cargo, pytest) ever
+ * compiles or executes: an image's bytes, a font's glyphs, an archive's
+ * contents. Changing one — including deleting it — leaves nothing for a test
+ * to observe, so it is neither test nor production (#4137).
+ *
+ * Observed on two real branches before this existed: #4114 (five deleted
+ * PNGs) and #4117 (an 87-file archive of JSON/patch/PNG evidence) both
+ * tripped `check-test-revert-oracle.mjs`'s "changes production code and
+ * adds/changes NO test file" ABORT — a false positive about the classifier,
+ * not a finding about either branch, since no test can observe a deleted
+ * PNG's absence.
+ *
+ * Deliberately narrow: this must NOT swallow anything a runner builds or
+ * runs. `.json` stays production (e.g. `package.json` gates behaviour via
+ * scripts/deps) — only formats with no runner-observable content at all are
+ * listed here.
+ */
+const INERT_SUFFIXES = [
+  // images
+  '.png', '.jpg', '.jpeg', '.gif', '.svg', '.ico', '.webp', '.avif', '.bmp', '.tiff', '.tif',
+  // fonts
+  '.woff', '.woff2', '.ttf', '.otf', '.eot',
+  // other binaries with no observable behaviour of their own
+  '.zip', '.gz', '.tar', '.pdf',
+];
+
+/** @param {string} path */
+export function isInertPath(path) {
+  const lower = path.toLowerCase();
+  return INERT_SUFFIXES.some((s) => lower.endsWith(s));
+}

scripts/lib/revert-oracle.mjs

@@ -35,19 +35,14 @@
  */
 
 import { parsePython, PYTEST_MISSING_PATTERN } from './revert-oracle-python.mjs';
+import { isInertPath } from './revert-oracle-inert.mjs';
 // ---------------------------------------------------------------------------
 // Diff classification
 // ---------------------------------------------------------------------------
 
 /** Paths whose change can neither be reverted usefully nor observed by a test. */
 const IGNORED_PREFIXES = ['.changeset/', '.github/', 'docs/', '.vscode/'];
-const IGNORED_EXACT = new Set([
-  'pnpm-lock.yaml',
-  'package-lock.json',
-  'yarn.lock',
-  'Cargo.lock',
-  'CHANGELOG.md',
-]);
+const IGNORED_EXACT = new Set(['pnpm-lock.yaml', 'package-lock.json', 'yarn.lock', 'Cargo.lock', 'CHANGELOG.md']);
 const IGNORED_SUFFIXES = ['.md', '.mdx', '.txt', '.snap.orig'];
 
 /**
@@ -83,7 +78,7 @@ export function classifyPath(path) {
   if (TEST_FILE_RE.test(path) || /(^|\/)(?:[^/]+_tests|tests)\.rs$/.test(path)) return 'test';
   if (TEST_DIR_RE.test(path)) return 'test';
   if (TEST_SEGMENT_RE.test(path)) return 'test';
-  return 'production';
+  return isInertPath(path) ? 'inert' : 'production';
 }
 
 /**
@@ -93,12 +88,12 @@ export function classifyDiff(entries) {
   const production = [];
   const test = [];
   const ignored = [];
+  const inert = [];
   const warnings = [];
   for (const { status, path } of entries) {
     const kind = classifyPath(path);
-    if (kind === 'production') production.push({ status, path });
-    else if (kind === 'test') test.push({ status, path });
-    else ignored.push({ status, path });
+    const bucket = kind === 'production' ? production : kind === 'test' ? test : kind === 'inert' ? inert : ignored;
+    bucket.push({ status, path });
   }
   if (production.some((e) => isRustFile(e.path))) {
     warnings.push(
@@ -107,7 +102,7 @@ export function classifyDiff(entries) {
         'as the code — expect INCONCLUSIVE and use --mutation for a surgical revert.',
     );
   }
-  return { production, test, ignored, warnings };
+  return { production, test, ignored, inert, warnings };
 }
 
 /** Parse `git diff --name-status -z`-free plain output. Renames carry two paths. */

scripts/lib/revert-oracle.test.mjs

@@ -498,6 +498,69 @@ test('classifyPath: the deploy-config rule does not swallow neighbouring code',
   assert.equal(classifyPath('vercel.json.ts'), 'production');
 });
 
+// WHY "inert" IS ITS OWN KIND, NOT `ignored` (#4137).
+//
+// A changed file that no runner in this repo claims as a test AND no runner
+// compiles or executes as source has no observable behaviour at all: an
+// image's bytes, a font's glyphs, an archive's contents. Classifying such a
+// file as `production` made the oracle ABORT with "changes production code
+// and adds/changes NO test file" on branches like #4114 (five deleted PNGs)
+// and #4117 (an 87-file archive) — there is no test that could possibly
+// accompany a deleted PNG, so the ABORT was a false positive about the
+// classifier, not a finding about the branch.
+test('classifyPath: images, fonts, and other binaries are inert, not production', () => {
+  assert.equal(classifyPath('apps/viewer/public/favicon-192x192.png'), 'inert');
+  assert.equal(classifyPath('apps/viewer/public/favicon.ico'), 'inert');
+  assert.equal(classifyPath('apps/viewer/src/assets/logo.svg'), 'inert');
+  assert.equal(classifyPath('apps/landing/public/hero.webp'), 'inert');
+  assert.equal(classifyPath('apps/viewer/public/fonts/inter.woff2'), 'inert');
+  assert.equal(classifyPath('apps/viewer/public/fonts/inter.ttf'), 'inert');
+  assert.equal(classifyPath('scripts/perf/evidence/report.pdf'), 'inert');
+  assert.equal(classifyPath('scripts/perf/evidence/archive.zip'), 'inert');
+});
+
+test('classifyPath: inertness is about the file kind, not the operation — a deleted image is still inert', () => {
+  // classifyPath is purely path-based; classifyDiff carries the `status` field
+  // through unchanged. A pure deletion of an inert file must not become
+  // production just because the "operation" is a delete (must-not-regress in
+  // #4137: inertness is about the file kind, not about the operation).
+  const { production, inert } = classifyDiff(parseNameStatus('D\tapps/viewer/public/favicon.png'));
+  assert.deepEqual(production, []);
+  assert.deepEqual(inert.map((e) => e.path), ['apps/viewer/public/favicon.png']);
+});
+
+test('classifyPath: inertness must NOT cover anything a runner compiles or executes', () => {
+  // Extensions a runner in this repo actually builds/executes stay production
+  // even though they sound "asset-like" or are commonly bundled alongside
+  // assets — this is the narrowing #4137 must preserve.
+  assert.equal(classifyPath('packages/core/package.json'), 'production');
+  assert.equal(classifyPath('crates/ifc-lite-geom/src/walk.rs'), 'production');
+  assert.equal(classifyPath('packages/renderer/src/device.ts'), 'production');
+  assert.equal(classifyPath('tools/ifcopenshell_reference/canonical.py'), 'production');
+});
+
+test('classifyDiff: a mixed diff keeps inert files out of BOTH production and test, without giving the real change a free pass', () => {
+  const entries = parseNameStatus(
+    [
+      'M\tpackages/renderer/src/device.ts',
+      'A\tapps/viewer/public/favicon-512x512.png',
+    ].join('\n'),
+  );
+  const { production, test: tests, inert } = classifyDiff(entries);
+  assert.deepEqual(production.map((e) => e.path), ['packages/renderer/src/device.ts']);
+  assert.deepEqual(tests, []);
+  assert.deepEqual(inert.map((e) => e.path), ['apps/viewer/public/favicon-512x512.png']);
+});
+
+test('classifyDiff: a diff of ONLY inert files has no production entries (script-level effect: NOT APPLICABLE, same as #4024 for test-only diffs)', () => {
+  const entries = parseNameStatus(
+    ['D\tapps/viewer/public/favicon-192x192.png', 'D\tapps/viewer/public/favicon-512x512.png'].join('\n'),
+  );
+  const { production, inert } = classifyDiff(entries);
+  assert.deepEqual(production, []);
+  assert.equal(inert.length, 2);
+});
+
 test('classifyDiff splits a real branch shape and never puts a test in production', () => {
   const entries = parseNameStatus(
     [