Support stdout (#387)

* Allow writing to stdout

* Fix CLI tests

* Update README

Author: drwpow

README.md

@@ -2,7 +2,9 @@
 [![codecov](https://codecov.io/gh/drwpow/openapi-typescript/branch/master/graph/badge.svg)](https://codecov.io/gh/drwpow/openapi-typescript)
 
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
+
 [![All Contributors](https://img.shields.io/badge/all_contributors-24-orange.svg?style=flat-square)](#contributors-)
+
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # 📘️ openapi-typescript
@@ -42,6 +44,12 @@ npx openapi-typescript https://petstore.swagger.io/v2/swagger.json --output pets
 
 _Thanks to @psmyrdek for this feature!_
 
+#### Outputting to `stdout`
+
+```bash
+npx openapi-typescript schema.yaml
+```
+
 #### Generating multiple schemas
 
 In your `package.json`, for each schema you’d like to transform add one `generate:specs:[name]` npm-script. Then combine
@@ -199,6 +207,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 
 <!-- markdownlint-enable -->
 <!-- prettier-ignore-end -->
+
 <!-- ALL-CONTRIBUTORS-LIST:END -->
 
 This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification.

bin/cli.js

@@ -13,7 +13,7 @@ const cli = meow(
 
 Options
   --help                display this
-  --output, -o          specify output file
+  --output, -o          (optional) specify output file (default: stdout)
   --prettier-config     (optional) specify path to Prettier config file
   --raw-schema          (optional) Read from raw schema instead of document
   --version             (optional) Schema version (must be present for raw schemas)
@@ -37,28 +37,38 @@ Options
   }
 );
 
-console.info(chalk.bold(`✨ openapi-typescript ${require("../package.json").version}`));
-
-const pathToSpec = cli.input[0];
 const timeStart = process.hrtime();
 
-(async () => {
-  let spec = "";
+async function main() {
+  let output = "FILE"; // FILE or STDOUT
+  const pathToSpec = cli.input[0];
+
+  // 0. setup
+  if (!cli.flags.output) {
+    output = "STDOUT"; // if --output not specified, fall back to stdout
+  }
+  if (output === "FILE") {
+    console.info(chalk.bold(`✨ openapi-typescript ${require("../package.json").version}`)); // only log if we’re NOT writing to stdout
+  }
+
+  // 1. input
+  let spec = undefined;
   try {
-    spec = await loadSpec(pathToSpec);
-  } catch (e) {
-    console.error(chalk.red(`❌ "${e}"`));
-    return;
+    spec = await loadSpec(pathToSpec, { log: output !== "STDOUT" });
+  } catch (err) {
+    throw new Error(chalk.red(`❌ ${err}`));
   }
 
+  // 2. generate schema (the main part!)
   const result = swaggerToTS(spec, {
     prettierConfig: cli.flags.prettierConfig,
     rawSchema: cli.flags.rawSchema,
     version: cli.flags.version,
   });
 
-  // Write to file if specifying output
-  if (cli.flags.output) {
+  // 3. output
+  if (output === "FILE") {
+    // output option 1: file
     const outputFile = path.resolve(process.cwd(), cli.flags.output);
 
     // recursively create parent directories if they don’t exist
@@ -74,10 +84,13 @@ const timeStart = process.hrtime();
 
     const timeEnd = process.hrtime(timeStart);
     const time = timeEnd[0] + Math.round(timeEnd[1] / 1e6);
-    console.log(chalk.green(`🚀 ${cli.input[0]} -> ${chalk.bold(cli.flags.output)} [${time}ms]`));
-    return;
+    console.log(chalk.green(`🚀 ${pathToSpec} -> ${chalk.bold(cli.flags.output)} [${time}ms]`));
+  } else {
+    // output option 2: stdout
+    process.stdout.write(result);
   }
 
-  // Otherwise, return result
   return result;
-})();
+}
+
+main();

bin/loaders/index.js

@@ -5,10 +5,11 @@ const loadFromFs = require("./loadFromFs");
 const loadFromHttp = require("./loadFromHttp");
 
 async function load(pathToSpec) {
-  let rawSpec;
+  // option 1: remote URL
   if (/^https?:\/\//.test(pathToSpec)) {
     try {
-      rawSpec = await loadFromHttp(pathToSpec);
+      const rawSpec = await loadFromHttp(pathToSpec);
+      return rawSpec;
     } catch (e) {
       if (e.code === "ENOTFOUND") {
         throw new Error(
@@ -17,18 +18,20 @@ async function load(pathToSpec) {
       }
       throw e;
     }
-  } else {
-    rawSpec = await loadFromFs(pathToSpec);
   }
-  return rawSpec;
+
+  // option 2: local file
+  return loadFromFs(pathToSpec);
 }
 
 function isYamlSpec(rawSpec, pathToSpec) {
   return /\.ya?ml$/i.test(pathToSpec) || rawSpec[0] !== "{";
 }
 
-module.exports.loadSpec = async (pathToSpec) => {
-  console.log(chalk.yellow(`🤞 Loading spec from ${chalk.bold(pathToSpec)}…`));
+module.exports.loadSpec = async (pathToSpec, { log = true }) => {
+  if (log === true) {
+    console.log(chalk.yellow(`🤞 Loading spec from ${chalk.bold(pathToSpec)}…`)); // only log if not writing to stdout
+  }
   const rawSpec = await load(pathToSpec);
 
   try {

bin/loaders/loadFromFs.js

@@ -5,16 +5,9 @@ module.exports = (pathToSpec) => {
   const pathname = path.resolve(process.cwd(), pathToSpec);
   const pathExists = fs.existsSync(pathname);
 
-  return new Promise((resolve, reject) => {
-    if (pathExists) {
-      fs.readFile(pathname, "UTF-8", (err, data) => {
-        if (err) {
-          reject(err);
-        }
-        resolve(data);
-      });
-    } else {
-      reject(`Cannot find spec under the following path: ${pathname}`);
-    }
-  });
+  if (!pathExists) {
+    throw new Error(`Cannot find spec under the following path: ${pathname}`);
+  }
+
+  return fs.readFileSync(pathname, "utf8");
 };

jest.config.js

@@ -1,4 +1,4 @@
 module.exports = {
-  preset: 'ts-jest',
-  testEnvironment: 'node',
+  preset: "ts-jest",
+  testEnvironment: "node",
 };