Revert "Don't limit to a concurrency of 1 now that harfbuzzjs auto-gr…

…ows the wasm heap"

Whoops, this breaks the subfont test suite.

This reverts commit e093995.

index.js

@@ -14,7 +14,7 @@ const loadAndInitializeHarfbuzz = _.once(async () => {
   return [exports, heapu8];
 });
 
-module.exports = async function subsetFont(
+async function subsetFont(
   originalFont,
   text,
   { targetFormat = fontverter.detectFormat(originalFont), preserveNameIds } = {}
@@ -113,4 +113,7 @@ module.exports = async function subsetFont(
   exports.free(fontBuffer);
 
   return await fontverter.convert(subsetFont, targetFormat, 'truetype');
-};
+}
+
+const limiter = require('p-limit')(1);
+module.exports = (...args) => limiter(() => subsetFont(...args));

package.json

@@ -6,7 +6,8 @@
   "dependencies": {
     "fontverter": "^2.0.0",
     "harfbuzzjs": "^0.3.0",
-    "lodash": "^4.17.21"
+    "lodash": "^4.17.21",
+    "p-limit": "^3.1.0"
   },
   "devDependencies": {
     "coveralls": "^3.0.2",