refactor: Remove lodash usages and make instantiatePreprocessor works…

… with cache and log errors
karma-runner · Oct 10, 2019 · 4ac9dd8 · 4ac9dd8
1 parent 4cee35c
commit 4ac9dd8
Showing 1 changed file with 25 additions and 28 deletions.
diff --git a/lib/preprocessor.js b/lib/preprocessor.js
@@ -3,7 +3,6 @@
 const fs = require('graceful-fs')
 const mm = require('minimatch')
 const isBinaryFile = require('isbinaryfile')
-const _ = require('lodash')
 const CryptoUtils = require('./utils/crypto-utils')
 
 const log = require('./logger').create('preprocess')
@@ -54,7 +53,10 @@ function createPriorityPreprocessor (config, preprocessorPriority, basePath, inj
       return
     }
 
-    let p
+    let p = instances[name]
+    if (p) {
+      return p
+    }
 
     try {
       p = injector.get('preprocessor:' + name)
@@ -68,13 +70,19 @@ function createPriorityPreprocessor (config, preprocessorPriority, basePath, inj
       emitter.emit('load_error', 'preprocessor', name)
     }
 
+    if (!p && !alreadyDisplayedErrors[name]) {
+      alreadyDisplayedErrors[name] = true
+      log.error(`Failed to instantiate preprocessor ${name}`)
+      emitter.emit('load_error', 'preprocessor', name)
+    } else {
+      instances[name] = p
+    }
+
     return p
   }
 
-  let allPreprocessors = []
-  patterns.forEach((pattern) => {
-    allPreprocessors = _.union(allPreprocessors, config[pattern])
-  })
+  const allPreprocessors = new Set()
+  patterns.forEach((pattern) => (config[pattern] || []).forEach((proc) => allPreprocessors.add(proc)))
   allPreprocessors.forEach(instantiatePreprocessor)
 
   return function preprocess (file, done) {
@@ -99,39 +107,28 @@ function createPriorityPreprocessor (config, preprocessorPriority, basePath, inj
           throw err
         }
 
-        let preprocessorNames = []
+        const preprocessorNames = new Set()
         patterns.forEach((pattern) => {
           if (mm(file.originalPath, pattern, { dot: true })) {
-            preprocessorNames = _.union(preprocessorNames, config[pattern])
+            (config[pattern] || []).forEach((name) => preprocessorNames.add(name))
           }
         })
 
         // Apply preprocessor priority.
-        let sortedPreprocessorNames = preprocessorNames
+        const preprocessors = Array.from(preprocessorNames)
           .map((name) => [name, preprocessorPriority[name] || 0])
           .sort((a, b) => b[1] - a[1])
           .map((duo) => duo[0])
+          .reduce((res, name) => {
+            const p = instantiatePreprocessor(name)
 
-        let preprocessors = []
-        sortedPreprocessorNames.forEach((name) => {
-          const p = instances[name] || instantiatePreprocessor(name)
-
-          if (p == null) {
-            if (!alreadyDisplayedErrors[name]) {
-              alreadyDisplayedErrors[name] = true
-              log.error(`Failed to instantiate preprocessor ${name}`)
-              emitter.emit('load_error', 'preprocessor', name)
+            if (!isBinary || (p && p.handleBinaryFiles)) {
+              res.push(p)
+            } else {
+              log.warn(`Ignored preprocessing ${file.originalPath} because ${name} has handleBinaryFiles=false.`)
             }
-            return
-          }
-
-          instances[name] = p
-          if (!isBinary || p.handleBinaryFiles) {
-            preprocessors.push(p)
-          } else {
-            log.warn(`Ignored preprocessing ${file.originalPath} because ${name} has handleBinaryFiles=false.`)
-          }
-        })
+            return res
+          }, [])
 
         runProcessors(preprocessors, file, isBinary ? buffer : buffer.toString()).then(done, done)
       })