Use the conversion tools introduced in #115 when creating a subset fo…

…nt with harfbuzz

lib/subsetLocalFontWithHarfbuzz.js

@@ -2,8 +2,7 @@
 const fs = require('fs');
 const readFileAsync = require('util').promisify(fs.readFile);
 const _ = require('lodash');
-const wawoff2 = require('wawoff2');
-const woffTool = require('woff2sfnt-sfnt2woff');
+const convertFontBuffer = require('./convertFontBuffer');
 
 function HB_TAG(chunkName) {
   return chunkName.split('').reduce(function (a, ch) {
@@ -26,12 +25,7 @@ const loadAndInitializeHarfbuzz = _.once(async () => {
 async function subset(originalFont, targetFormat, text) {
   const [exports, heapu8] = await loadAndInitializeHarfbuzz();
 
-  const signature = originalFont.slice(0, 4).toString();
-  if (signature === 'wOFF') {
-    originalFont = woffTool.toSfnt(originalFont);
-  } else if (signature === 'wOF2') {
-    originalFont = await wawoff2.decompress(originalFont);
-  }
+  originalFont = await convertFontBuffer(originalFont, 'truetype');
 
   const fontBuffer = exports.malloc(originalFont.byteLength);
   heapu8.set(new Uint8Array(originalFont), fontBuffer);
@@ -79,24 +73,15 @@ async function subset(originalFont, targetFormat, text) {
   const result = exports.hb_face_reference_blob(subset);
 
   const offset = exports.hb_blob_get_data(result, 0);
-  let subsetFont = heapu8.slice(
-    offset,
-    offset + exports.hb_blob_get_length(result)
+  const subsetFont = Buffer.from(
+    heapu8.slice(offset, offset + exports.hb_blob_get_length(result))
   );
 
   // Clean up
   exports.hb_blob_destroy(result);
   exports.hb_face_destroy(subset);
 
-  if (targetFormat === 'woff2') {
-    subsetFont = Buffer.from(await wawoff2.compress(subsetFont));
-  } else if (targetFormat === 'woff') {
-    subsetFont = woffTool.toWoff(subsetFont);
-  } else {
-    // targetFormat === 'truetype'
-    subsetFont = Buffer.from(subsetFont);
-  }
-  return subsetFont;
+  return await convertFontBuffer(subsetFont, targetFormat, 'truetype');
 }
 
 const limiter = require('p-limit')(1);

test/subsetLocalFontWithHarfbuzz.js

@@ -18,7 +18,7 @@ describe('subsetLocalFontWithHarfbuzz', function () {
       );
       const result = await subsetLocalFontWithHarfbuzz(
         openSansTtf,
-        'ttf',
+        'truetype',
         'abcd'
       );
 
@@ -84,7 +84,7 @@ describe('subsetLocalFontWithHarfbuzz', function () {
       );
       const result = await subsetLocalFontWithHarfbuzz(
         openSansWoff,
-        'ttf',
+        'truetype',
         'abcd'
       );
 
@@ -147,7 +147,7 @@ describe('subsetLocalFontWithHarfbuzz', function () {
       );
       const result = await subsetLocalFontWithHarfbuzz(
         openSansWoff,
-        'ttf',
+        'truetype',
         'abcd'
       );