CLI usage updates (#53)

* cli usage updates

* implement run

* implement render output, flatten asset output

readme.md

@@ -22,9 +22,11 @@ together with all its dependencies, gcc-style.
 ### CLI
 
 ```bash
-$ ncc input.js -o bundle.js
+$ ncc build input.js -o dist
 ```
 
+Outputs the build of `input.js` into `dist/index.js`.
+
 ### Node.js
 
 ```js

src/cli.js

@@ -1,58 +1,132 @@
-const { resolve } = require("path");
+const { resolve, relative, dirname, sep } = require("path");
 const args = require("arg")({
-  "--help": Boolean,
-  "-h": "--help",
   "--external": [String],
   "-e": "--external",
   "--out": String,
   "-o": "--out",
   "--no-minify": Boolean,
-  M: "--no-minify"
+  M: "--no-minify",
+  "--quiet": Boolean,
+  "-q": "--quiet"
 });
 
-const usage = `ncc build <input-file> [opts]
+const usage = `Usage: ncc <cmd> <opts>
+
+Commands:
+  build <input-file> [opts]
+  run <input-file> [opts]
+  help
+  version
+
 Options:
+  -o, --out [file]      Output directory for build (defaults to dist)
   -M, --no-minify       Skip output minification
   -e, --external [mod]  Skip bundling 'mod'. Can be used many times
-  -o, --out [file]      Output directory (defaults to dist)
-  -h, --help            Show help
+  -q, --quiet           Disable build summaries / non-error outputs
 `;
 
-if (args["--help"]) {
-  console.error(usage);
-  process.exit(2);
+function renderSummary (code, assets, outDir, buildTime) {
+  if (!outDir.endsWith(sep))
+    outDir += sep;
+  const codeSize = Math.round(Buffer.byteLength(code, 'utf8') / 1024);
+  const assetSizes = Object.create(null);
+  let maxSize = codeSize;
+  let maxAssetNameLength = 8; // "index.js".length
+  for (const asset of Object.keys(assets)) {
+    const assetSource = assets[asset];
+    const assetSize = Math.round((assetSource.byteLength || Buffer.byteLength(assetSource, 'utf8')) / 1024);
+    assetSizes[asset] = assetSize;
+    if (assetSize > maxSize)
+      maxSize = assetSize;
+    if (asset.length > maxAssetNameLength)
+      maxAssetNameLength = asset.length;
+  }
+  const orderedAssets = Object.keys(assets).sort((a, b) => assetSizes[a] > assetSizes[b] ? 1 : -1);
+
+  const sizePadding = maxSize.toString().length;
+
+  const indexRender = `${codeSize.toString().padStart(sizePadding, ' ')}kB  ${outDir}${'index.js'.padEnd(maxAssetNameLength, ' ')}   [${buildTime}ms]\n`;
+
+  let output = "", first = true;
+  for (const asset of orderedAssets) {
+    if (first)
+      first = false;
+    else
+      output += "\n";
+    if (codeSize < assetSizes[asset])
+      output += indexRender;
+    output += `${assetSizes[asset].toString().padStart(sizePadding, ' ')}kB  ${outDir}${asset}`
+  }
+
+  if (maxSize === codeSize)
+    output += (first ? "" : "\n") + indexRender;
+
+  return output;
 }
 
 if (args._.length === 0) {
   console.error(`Error: No command specified\n${usage}`);
   process.exit(1);
 }
 
+let run = false;
+let outDir = args["--out"];
+
 switch (args._[0]) {
+  case "run":
+    if (args._.length > 2) {
+      console.error(`Error: Too many run arguments provided\n${usage}`);
+      process.exit(1);
+    }
+    if (args["--out"]) {
+      console.error(`Error: --out flag is not compatible with ncc run\n${usage}`);
+      process.exit(1);
+    }
+    outDir = resolve(require("os").tmpdir(), Math.random().toString(16).substr(2));
+    run = true;
+
+    // fallthrough
   case "build":
     if (args._.length > 2) {
       console.error(`Error: Too many build arguments provided\n${usage}`);
       process.exit(1);
     }
 
-    const ncc = require("./index.js")(resolve(args._[1] || "."), {
+    const startTime = Date.now();
+    const ncc = require("./index.js")(eval("require.resolve")(resolve(args._[1] || ".")), {
       minify: !args["--no-minify"],
       externals: args["--external"]
     });
 
     ncc.then(({ code, assets }) => {
-      const outDir = args["--out"] || resolve("dist");
+      outDir = outDir || resolve("dist");
       const fs = require("fs");
       const mkdirp = require("mkdirp");
       mkdirp.sync(outDir);
       fs.writeFileSync(outDir + "/index.js", code);
       for (const asset of Object.keys(assets)) {
-        mkdirp.sync(path.dirname(asset));
+        mkdirp.sync(dirname(asset));
         fs.writeFileSync(outDir + "/" + asset, assets[asset]);
       }
+
+      if (!args['--quiet'])
+        console.log(renderSummary(code, assets, run ? '' : relative(process.cwd(), outDir), Date.now() - startTime));
+
+      if (run) {
+        const ps = require("child_process").fork(outDir + "/index.js");
+        ps.on("close", () => require("rimraf").sync(outDir));
+      }
     });
   break;
 
+  case "help":
+    console.error(usage);
+    process.exit(2);
+
+  case "version":
+    console.log(require('../package.json').version);
+  break;
+
   default:
     console.error(`Error: Invalid command "${args._[0]}"\n${usage}`);
     process.exit(1);