Factor out config validation into own module

cli/index.js

@@ -86,20 +86,19 @@ if (opts['server-option']) {
   opts.server_options = opts['server-option'];
 }
 
-(async () => {
-  if (opts._.length) {
-    if (opts._[0] === '-') {
-      opts.spec = process.stdin;
-    } else {
-      opts.spec = opts._;
-    }
+if (opts._.length) {
+  if (opts._[0] === '-') {
+    opts.spec = process.stdin;
+  } else {
+    opts.spec = opts._;
   }
-  delete opts._;
-  try {
-    const { exit_code } = await mochify(opts);
-    process.exitCode = exit_code; // eslint-disable-line require-atomic-updates
-  } catch (e) {
-    console.error(e.stack);
-    process.exitCode = 1; // eslint-disable-line require-atomic-updates
-  }
-})();
+}
+delete opts._;
+mochify(opts)
+  .catch((err) => {
+    console.error(err.stack);
+    return { exit_code: 1 };
+  })
+  .then(({ exit_code }) => {
+    process.exitCode = exit_code;
+  });

mochify/index.js

@@ -2,6 +2,7 @@
 
 const { readFile } = require('fs').promises;
 const { loadConfig } = require('./lib/load-config');
+const { validateConfig } = require('./lib/validate-config');
 const { setupClient } = require('./lib/setup-client');
 const { createMochaRunner } = require('./lib/mocha-runner');
 const { resolveBundle } = require('./lib/resolve-bundle');
@@ -14,6 +15,11 @@ exports.mochify = mochify;
 async function mochify(options = {}) {
   const config = await loadConfig(options);
 
+  const validation_error = validateConfig(config);
+  if (validation_error) {
+    throw validation_error;
+  }
+
   // Create runner early to verify the reporter exists:
   const mocha_runner = createMochaRunner(config.reporter || 'spec');
   const { mochifyDriver } = resolveMochifyDriver(config.driver);

mochify/lib/load-config.js

@@ -10,20 +10,13 @@ async function loadConfig(options) {
 
   const default_config_promise = explorer.search();
 
-  let merged;
   if (options.config) {
     const specified = await explorer.load(options.config);
     const config = Object.assign(specified.config, options);
-    merged = await mergeWithDefault(default_config_promise, config);
-  } else {
-    merged = await mergeWithDefault(default_config_promise, options);
+    return mergeWithDefault(default_config_promise, config);
   }
 
-  const validation_error = validate(merged);
-  if (validation_error) {
-    throw validation_error;
-  }
-  return merged;
+  return mergeWithDefault(default_config_promise, options);
 }
 
 async function mergeWithDefault(default_config_promise, config) {
@@ -35,17 +28,3 @@ async function mergeWithDefault(default_config_promise, config) {
   }
   return config;
 }
-
-function validate(config) {
-  if (config.esm && config.bundle) {
-    return new Error('`esm` cannot be used in conjunction with `bundle`');
-  }
-  if (
-    config.bundle &&
-    typeof config.spec === 'object' &&
-    typeof config.spec.pipe === 'function'
-  ) {
-    return new Error('`bundle` cannot be used when `spec` is a stream.');
-  }
-  return null;
-}

mochify/lib/load-config.test.js

@@ -154,14 +154,4 @@ describe('mochify/lib/load-config', () => {
       reporter: 'nyan'
     });
   });
-
-  it('rejects on invalid configuration', async () => {
-    setDefaultConfig({ esm: true });
-    setSpecifiedConfig({ bundle: 'browserify' });
-    const loadConfig = requireLoadConfig();
-
-    const promise = loadConfig({ config: 'some.config.js' });
-
-    await assert.rejects(promise);
-  });
 });

mochify/lib/validate-config.js

@@ -0,0 +1,17 @@
+'use strict';
+
+exports.validateConfig = validateConfig;
+
+function validateConfig(config) {
+  if (config.esm && config.bundle) {
+    return new Error('`esm` cannot be used in conjunction with `bundle`');
+  }
+  if (
+    config.bundle &&
+    typeof config.spec === 'object' &&
+    typeof config.spec.pipe === 'function'
+  ) {
+    return new Error('`bundle` cannot be used when `spec` is a stream.');
+  }
+  return null;
+}

mochify/lib/validate-config.test.js

@@ -0,0 +1,36 @@
+'use strict';
+
+const fs = require('fs');
+const { assert } = require('@sinonjs/referee-sinon');
+const { validateConfig } = require('./validate-config');
+
+describe('mochify/lib/validate-config', () => {
+  it('returns an error when esm and bundle are given', () => {
+    assert.isError(
+      validateConfig({ esm: true, bundle: 'browserify', spec: './test.js' })
+    );
+  });
+
+  it('returns an error when bundle and a stream spec are given', () => {
+    assert.isError(
+      validateConfig({
+        bundle: 'browserify',
+        spec: fs.createReadStream(__filename)
+      })
+    );
+  });
+
+  it('returns null on an empty config', () => {
+    assert.isNull(validateConfig({}));
+  });
+
+  it('returns null on a valid config', () => {
+    assert.isNull(
+      validateConfig({
+        bundle: 'browserify -t babelify',
+        spec: './test.js',
+        driver: 'puppeteer'
+      })
+    );
+  });
+});