🧪 Add error path tests for expectString

scripts/validate-metadata.js

@@ -195,5 +195,5 @@ module.exports = {
   parseMetadataYaml,
   normalizeModelKey,
   listMetadataFiles,
-  setNested,
+  expectString,
 };

scripts/validate-metadata.test.js

@@ -1,6 +1,6 @@
 const test = require('node:test');
 const assert = require('node:assert');
-const { parseMetadataYaml, listMetadataFiles, setNested } = require('./validate-metadata.js');
+const { parseMetadataYaml, listMetadataFiles, setNested, expectString } = require('./validate-metadata.js');
 
 test('setNested', async (t) => {
   await t.test('sets a single property', () => {
@@ -275,6 +275,38 @@ tags:
   });
 });
 
+test('expectString', async (t) => {
+  await t.test('appends error if value is not a string', () => {
+    const errors = [];
+    expectString(errors, 123, 'label', 'file.txt');
+    assert.deepStrictEqual(errors, ['file.txt: missing or invalid label']);
+  });
+
+  await t.test('appends error if value is null', () => {
+    const errors = [];
+    expectString(errors, null, 'label', 'file.txt');
+    assert.deepStrictEqual(errors, ['file.txt: missing or invalid label']);
+  });
+
+  await t.test('appends error if string is empty', () => {
+    const errors = [];
+    expectString(errors, '', 'label', 'file.txt');
+    assert.deepStrictEqual(errors, ['file.txt: missing or invalid label']);
+  });
+
+  await t.test('appends error if string is only whitespace', () => {
+    const errors = [];
+    expectString(errors, '   \n  ', 'label', 'file.txt');
+    assert.deepStrictEqual(errors, ['file.txt: missing or invalid label']);
+  });
+
+  await t.test('does not append error for valid string', () => {
+    const errors = [];
+    expectString(errors, 'valid string', 'label', 'file.txt');
+    assert.deepStrictEqual(errors, []);
+  });
+});
+
 test('listMetadataFiles', async (t) => {
   await t.test('returns empty array for non-existent directory', () => {
     const nonExistentPath = '/path/that/does/not/exist/for/sure/12345';