Validate config right after merging

mochify/lib/load-config.js

@@ -10,13 +10,20 @@ 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);
-    return mergeWithDefault(default_config_promise, config);
+    merged = await mergeWithDefault(default_config_promise, config);
+  } else {
+    merged = await mergeWithDefault(default_config_promise, options);
   }
 
-  return mergeWithDefault(default_config_promise, options);
+  const validation_error = validate(merged);
+  if (validation_error) {
+    throw validation_error;
+  }
+  return merged;
 }
 
 async function mergeWithDefault(default_config_promise, config) {
@@ -28,3 +35,17 @@ 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

@@ -154,4 +154,14 @@ 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/resolve-bundle.js

@@ -7,25 +7,8 @@ const { parseArgsStringToArgv } = require('string-argv');
 exports.resolveBundle = resolveBundle;
 
 async function resolveBundle(command, files) {
-  if (command && files) {
-    throw new Error(
-      'Cannot use a stream as input when a bundle command is given.'
-    );
-  }
-
   if (typeof files === 'object' && typeof files.pipe === 'function') {
-    return new Promise((resolve, reject) => {
-      let buf;
-      files.on('data', (data) => {
-        buf += data;
-      });
-      files.on('error', (err) => {
-        reject(err);
-      });
-      files.on('end', () => {
-        resolve(buf);
-      });
-    });
+    return bufferStream(files);
   }
 
   if (!command) {
@@ -49,3 +32,12 @@ async function concatFiles(files) {
   const buffers = await Promise.all(files.map((file) => fs.readFile(file)));
   return Buffer.concat(buffers).toString('utf8');
 }
+
+function bufferStream(stream) {
+  return new Promise((resolve, reject) => {
+    const bs = [];
+    stream.on('data', (chunk) => bs.push(chunk));
+    stream.on('error', (err) => reject(err));
+    stream.on('end', () => resolve(Buffer.concat(bs).toString()));
+  });
+}

mochify/lib/resolve-spec.test.js

@@ -1,5 +1,6 @@
 'use strict';
 
+const fs = require('fs');
 const proxyquire = require('proxyquire');
 const { assert, sinon } = require('@sinonjs/referee-sinon');
 
@@ -75,4 +76,10 @@ describe('mochify/lib/resolve-spec', () => {
 
     await assert.rejects(promise, error);
   });
+
+  it('passes through streams', async () => {
+    const stream = fs.createReadStream(__filename);
+    const promise = resolveSpec(stream);
+    await assert.resolves(promise, stream);
+  });
 });