paralelize tasks using Promise.all

xgbuils · May 29, 2019 · c20eea1 · c20eea1
1 parent cc5c921
commit c20eea1
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Showing 4 changed files with 80 additions and 58 deletions.
diff --git a/src/features-provider/features-provider.js b/src/features-provider/features-provider.js
@@ -1,4 +1,4 @@
-const {flatMap, uniq} = require('../utils/generic');
+const {flatMap, flatten, uniq} = require('../utils/generic');
 const glob = require('glob');
 const fs = require('fs');
 const path = require('path');
@@ -50,6 +50,17 @@ const reportFailure = (pattern) => {
   });
 };
 
+const getFileNames = (globOptions) => (pattern) => {
+  const globPatterns = getGlobPatterns(pattern, '**/*.feature');
+  const fileNames = filterFeatures(flatMap((globPattern) => {
+    return glob.sync(globPattern, globOptions);
+  })(globPatterns));
+  if (fileNames.length === 0) {
+    return reportFailure(pattern);
+  }
+  return Promise.resolve(fileNames);
+};
+
 class FeatureProvider {
   constructor(args, {ignore = defaults.ignore, cwd}) {
     this.args = args;
@@ -65,23 +76,9 @@ class FeatureProvider {
       ignore: getIgnorePatterns(ignore, cwd),
       cwd,
     };
-    let resultPromise = Promise.resolve([]);
-    for (let index = 0; index < patterns.length; ++index) {
-      const pattern = patterns[index];
-      const globPatterns = getGlobPatterns(pattern, '**/*.feature');
-      const fileNames = filterFeatures(flatMap((globPattern) => {
-        return glob.sync(globPattern, globOptions);
-      })(globPatterns));
-      if (fileNames.length === 0) {
-        return reportFailure(pattern);
-      }
-      resultPromise = resultPromise.then((result) => {
-        result.push(...fileNames);
-        return result;
-      });
-    }
-
-    return resultPromise.then((files) => parseFileList(files));
+    return Promise.all(patterns.map(getFileNames(globOptions)))
+      .then(flatten)
+      .then(parseFileList);
   }
 }
 

diff --git a/src/linter/index.js b/src/linter/index.js
@@ -1,22 +1,22 @@
+const {flatten} = require('../utils/generic');
+
 const sortByLine = (errors) => errors.sort((a, b) => {
   return a.location.line - b.location.line;
 });
 
+const lintFileWith = (fileLinter, rules) => (file) => {
+  return fileLinter.lint(file, rules).then((fileErrors) => {
+    return fileErrors.length > 0 ? [{
+      message: file.path,
+      errors: sortByLine(fileErrors),
+    }] : [];
+  });
+};
+
 const lintFiles = (files, rules, fileLinter) => {
-  const outputPromise = files.reduce((errorsPromise, file) => {
-    return errorsPromise.then((errors) => {
-      return fileLinter.lint(file, rules).then((fileErrors) => {
-        if (fileErrors.length > 0) {
-          const fileBlob = {
-            message: file.path,
-            errors: sortByLine(fileErrors),
-          };
-          errors.push(fileBlob);
-        }
-        return errors;
-      });
-    });
-  }, Promise.resolve([]));
+  const lintFile = lintFileWith(fileLinter, rules);
+  const outputPromise = Promise.all(files.map(lintFile))
+    .then(flatten);
 
   return outputPromise.then((output) => {
     return output.length > 0

diff --git a/src/rules-parser.js b/src/rules-parser.js
@@ -1,4 +1,5 @@
 const enablingSettings = ['on', 'off'];
+const {flatten} = require('./utils/generic');
 const RuleCommand = require('./rule-command');
 
 function isValidEnablingSetting(enablingSetting) {
@@ -59,35 +60,56 @@ function normalizeRule(rules, config, ruleName) {
   }
 }
 
-function RuleParser(rules) {
-  this.rules = rules;
-}
+const getRuleResultPromises = (rules, config) => {
+  return Object.keys(config).map((ruleName) => {
+    return normalizeRule(rules, config, ruleName);
+  });
+};
 
-const append = (result, array) => {
-  result.push(...array);
-  return result;
+const getErrors = (prom) => {
+  return prom.then(
+    (result) => [],
+    (errors) => (errors)
+  );
 };
 
-RuleParser.prototype.parse = function(config) {
-  const {rules} = this;
-  const resultPromise = Object.keys(config).reduce(function(resultPromise, ruleName) {
-    const rulePromise = normalizeRule(rules, config, ruleName);
-    return resultPromise.then(
-      (result) => rulePromise.then(
-        (rules) => append(result, rules),
-        (errors) => Promise.reject(errors)
-      ),
-      (errorResults) => rulePromise.then(
-        (rules) => Promise.reject(errorResults),
-        (errorRules) => Promise.reject(append(errorResults, errorRules))
-      )
-    );
-  }, Promise.resolve([]));
-  return resultPromise.catch((errors) => Promise.reject({
-    type: 'config-error',
-    message: 'Error(s) in configuration file:',
-    errors,
-  }));
+const filterRules = (rulePromises) => {
+  return Promise.all(rulePromises).then(
+    flatten,
+    () => []
+  );
 };
 
+const filterErrors = (rulePromises) => {
+  return Promise.all(rulePromises.map(getErrors))
+    .then(flatten)
+    .then((errors) => {
+      return errors.length > 0 ? Promise.reject(errors) : [];
+    });
+};
+
+const buildConfigErrors = (errors) => ({
+  type: 'config-error',
+  message: 'Error(s) in configuration file:',
+  errors,
+});
+
+class RuleParser {
+  constructor(rules) {
+    this.rules = rules;
+  }
+
+  parse(config) {
+    const {rules} = this;
+    const promises = getRuleResultPromises(rules, config);
+    const rulesPromise = filterRules(promises);
+    const errorsPromise = filterErrors(promises);
+    return Promise.all([rulesPromise, errorsPromise])
+      .then(
+        ([rules]) => rules,
+        (errors) => Promise.reject(buildConfigErrors(errors))
+      );
+  }
+}
+
 module.exports = RuleParser;
diff --git a/src/utils/generic.js b/src/utils/generic.js
@@ -37,13 +37,16 @@ const applyAfter = (appendedCheck) => (check) => applyOver([
 
 const uniq = (array) => [...new Set(array)];
 
+const flatten = flatMap((items) => items);
+
 module.exports = {
   append,
   applyAfter,
   applyOver,
   applyWith,
   compose,
   flatMap,
+  flatten,
   intoArray,
   reduce,
   uniq,