Add command to process with tailwind from file with custom json config

src/index.js

@@ -0,0 +1,54 @@
+#!/usr/bin/env node
+
+import fs from 'fs'
+import path from 'path'
+import postcss from 'postcss'
+import defaultConfig from './defaultConfig'
+import program from 'commander'
+import tailwind from './tailwind'
+
+let splitFileName = filename => {
+  return filename.split('.')
+}
+
+program
+  .version('0.1.0')
+  .usage('[options] <file ...>')
+  .option('-c, --config [value]', 'Pass custom configuration')
+  .parse(process.argv)
+
+let inputFile = program.args[0]
+let outputFile =
+  program.args[1] || `${splitFileName(program.args[0])[0]}-output.css`
+
+if (!inputFile) {
+  console.error('No input file given!')
+  process.exit(1)
+}
+
+fs.readFile(path.join(program.config), (err, config) => {
+  if (err) {
+    console.error(`config file ${program.config} does not exist`)
+    process.exit(1)
+  }
+
+  const customConfig = JSON.parse(config.toString())
+
+  let finalConfig = {
+    ...defaultConfig,
+    ...customConfig,
+  }
+
+  console.log('Building Tailwind!')
+
+  fs.readFile(inputFile, (err, css) => {
+    postcss([tailwind(finalConfig)])
+      .process(css)
+      .then(result => {
+        fs.writeFileSync(outputFile, result.css)
+      })
+      .catch(error => console.log(error))
+  })
+
+  console.log('Finished building Tailwind!')
+})