Generate fontMetricsData as JavaScript

Makefile

@@ -83,7 +83,7 @@ PERL=perl
 PYTHON=$(shell python2 --version >/dev/null 2>&1 && echo python2 || echo python)
 
 metrics:
-	cd metrics && $(PERL) ./mapping.pl | $(PYTHON) ./extract_tfms.py | $(PYTHON) ./extract_ttfs.py | $(PYTHON) ./format_json.py > ../src/fontMetricsData.json
+	cd metrics && $(PERL) ./mapping.pl | $(PYTHON) ./extract_tfms.py | $(PYTHON) ./extract_ttfs.py | $(PYTHON) ./format_json.py > ../src/fontMetricsData.js
 
 clean:
 	rm -rf build/*

metrics/format_json.py

@@ -4,7 +4,7 @@ import sys
 import json
 
 data = json.load(sys.stdin)
-sep = "{\n"
+sep = "module.exports = {\n"
 for font in sorted(data):
   sys.stdout.write(sep + json.dumps(font))
   sep = ": {\n  "

src/fontMetricsData.js

@@ -1,4 +1,4 @@
-{
+module.exports = {
 "AMS-Regular": {
   "65": {"depth": 0.0, "height": 0.68889, "italic": 0.0, "skew": 0.0},
   "66": {"depth": 0.0, "height": 0.68889, "italic": 0.0, "skew": 0.0},