Add build script

build.js

@@ -0,0 +1,95 @@
+const fs = require('fs');
+const exec = require('child_process').execSync;
+
+const config = {
+  lettersPath: './Letters/',
+  inputPath: './src/',
+  outputPath: './dist/',
+};
+
+async function genTextsFromFile() {
+  const textDir = await fs.promises
+    .readdir(config.lettersPath)
+    .catch(err => console.error(err));
+  let letters = '';
+  let num = 0;
+
+  for (let i = 0; i < textDir.length; i++) {
+    const textFile = textDir[i];
+    let textFilePath = config.lettersPath + textFile;
+
+    const letter = await fs.promises
+      .readFile(textFilePath, 'utf-8')
+      .catch(err => console.error(err));
+
+    letters += letter;
+    num++;
+
+    if (num === textDir.length) {
+      return letters;
+    }
+  }
+}
+
+async function getSrcFonts() {
+  const inputDir = await fs.promises
+    .readdir(config.inputPath)
+    .catch(err => console.error(err));
+
+  return inputDir.filter(fontFile => {
+    return (
+      fs.statSync(config.inputPath + fontFile).isFile() &&
+      /.*\.otf$/.test(fontFile)
+    );
+  });
+}
+
+const subset = async () => {
+  const [text, srcFonts] = await Promise.all([
+    genTextsFromFile(),
+    getSrcFonts(),
+  ]);
+  const tmpTextFile = 'tmpTextFile.txt';
+
+  await fs.promises
+    .writeFile(tmpTextFile, text)
+    .catch(err => console.error(err));
+
+  if (!fs.existsSync(config.outputPath)) {
+    fs.mkdirSync(config.outputPath);
+  }
+
+  srcFonts.forEach((fontFile, fontIndex) => {
+    const reg = /(.*)(?:\.([^.]+$))/;
+    const fontName = fontFile.match(reg)[1];
+
+    const extensions = ['ttf', 'woff', 'woff2'];
+
+    extensions.forEach((ext, extIndex) => {
+      const flavorOpt =
+        ext === 'woff' || ext === 'woff2' ? `--flavor=${ext} --with-zopfli --desubroutinize` : '';
+      const command = `pyftsubset ./${
+        config.inputPath
+      }${fontFile} --text-file=./${tmpTextFile} --layout-features='*' --output-file=./${
+        config.outputPath
+      }${fontName}.min.${ext} --no-hinting ${flavorOpt}`;
+
+      try {
+        exec(command);
+      } catch (e) {
+        console.error(err);
+      } finally {
+        if (
+          fontIndex + 1 >= srcFonts.length &&
+          extIndex + 1 >= extensions.length
+        ) {
+          fs.unlink(tmpTextFile, err => {
+            if (err) throw err;
+          });
+        }
+      }
+    });
+  });
+};
+
+module.exports = subset();