os2: Fill Panose when writing font

src/tables/os2.mjs

@@ -165,6 +165,16 @@ function parseOS2Table(data, start) {
     for (let i = 0; i < 10; i++) {
         os2.panose[i] = p.parseByte();
     }
+    os2.bFamilyType = os2.panose[0];
+    os2.bSerifStyle = os2.panose[1];
+    os2.bWeight = os2.panose[2];
+    os2.bProportion = os2.panose[3];
+    os2.bContrast = os2.panose[4];
+    os2.bStrokeVariation = os2.panose[5];
+    os2.bArmStyle = os2.panose[6];
+    os2.bLetterform = os2.panose[7];
+    os2.bMidline = os2.panose[8];
+    os2.bXHeight = os2.panose[9];
 
     os2.ulUnicodeRange1 = p.parseULong();
     os2.ulUnicodeRange2 = p.parseULong();

test/tables/os2.spec.mjs

@@ -0,0 +1,33 @@
+import assert from 'assert';
+import { parse } from '../../dist/opentype.mjs';
+import { readFileSync } from 'fs';
+const loadSync = (url, opt) => parse(readFileSync(url), opt);
+
+describe('tables/os2.mjs', function () {
+    const font = loadSync('./test/fonts/AbrilFatface-Regular.otf');
+    const testData = {
+        achVendID: 'TT\x00\x00',
+        usWeightClass: 400,
+        bFamilyType: 2,
+        bSerifStyle: 0,
+        bWeight: 5,
+        bProportion: 3,
+        bContrast: 0,
+        bStrokeVariation: 0,
+        bArmStyle: 0,
+        bLetterform: 2,
+        bMidline: 0,
+        bXHeight: 3,
+    };
+    it('can read some OS2 table entries from file', function () {
+        for (const k in testData) {
+            assert.equal(font.tables.os2[k], testData[k]);
+        }
+    });
+    const font2 = parse(font.toArrayBuffer());
+    it('can write some OS2 table entries', function () {
+        for (const k in testData) {
+            assert.equal(font2.tables.os2[k], testData[k]);
+        }
+    });
+});