Implement support for a preserveNameIds array

index.js

@@ -18,7 +18,7 @@ const loadAndInitializeHarfbuzz = _.once(async () => {
 async function subsetFont(
   originalFont,
   text,
-  { targetFormat = fontverter.detectFormat(originalFont) } = {}
+  { targetFormat = fontverter.detectFormat(originalFont), preserveNameIds } = {}
 ) {
   const [exports, heapu8] = await loadAndInitializeHarfbuzz();
 
@@ -40,6 +40,13 @@ async function subsetFont(
 
   const input = exports.hb_subset_input_create_or_fail();
 
+  if (preserveNameIds) {
+    const inputNameIds = exports.hb_subset_input_nameid_set(input);
+    for (const nameId of preserveNameIds) {
+      exports.hb_set_add(inputNameIds, nameId);
+    }
+  }
+
   // Add unicodes indices
   const inputUnicodes = exports.hb_subset_input_unicode_set(input);
   for (const c of text) {

package.json

@@ -18,6 +18,8 @@
     "eslint-plugin-node": "^11.0.0",
     "eslint-plugin-promise": "^4.0.1",
     "eslint-plugin-standard": "^5.0.0",
+    "fast-xml-parser": "^3.19.0",
+    "gettemporaryfilepath": "^1.0.1",
     "mocha": "^7.0.0",
     "nyc": "^15.0.0",
     "offline-github-changelog": "^2.0.0",

test/index.js

@@ -1,4 +1,28 @@
-const expect = require('unexpected');
+const childProcess = require('child_process');
+const getTemporaryFilePath = require('gettemporaryfilepath');
+const fs = require('fs').promises;
+
+const expect = require('unexpected')
+  .clone()
+  .addAssertion(
+    '<Buffer> [not] to have name id <number>',
+    async (expect, fontBuffer, nameId) => {
+      const outputFile = getTemporaryFilePath({ suffix: '.ttf' });
+      await fs.writeFile(outputFile, fontBuffer);
+      const xmlBuffer = childProcess.execSync(`ttx -t name -o - ${outputFile}`);
+      const nameRecords = require('fast-xml-parser').parse(
+        xmlBuffer.toString(),
+        {
+          ignoreAttributes: false,
+          parseAttributeValue: true,
+        }
+      ).ttFont.name.namerecord;
+      expect.errorMode = 'nested';
+      expect(nameRecords, '[not] to have an item satisfying', {
+        '@_nameID': nameId,
+      });
+    }
+  );
 const subsetFont = require('..');
 const fontverter = require('fontverter');
 const { readFile } = require('fs').promises;
@@ -51,6 +75,25 @@ describe('subset-font', function () {
       expect(result.length, 'to be less than', this.sfntFont.length);
       expect(result.slice(0, 4).toString(), 'to equal', 'wOF2');
     });
+
+    describe('when not preserving any name ids', function () {
+      it('should not preserve name id 14', async function () {
+        const result = await subsetFont(this.sfntFont, 'abcd');
+        await expect(result, 'not to have name id', 14);
+      });
+    });
+
+    describe('when preserving only name id 14', function () {
+      before(async function () {
+        this.result = await subsetFont(this.sfntFont, 'abcd', {
+          preserveNameIds: [14],
+        });
+      });
+
+      it('should preserve name id 14', async function () {
+        await expect(this.result, 'to have name id', 14);
+      });
+    });
   });
 
   describe('with a woff font', function () {