Use for-of in place of .forEach() iteration.

lib/Snippets.js

@@ -17,7 +17,8 @@ class Snippets {
   getTests() {
     var tests = [];
     var evaluatedExampleIndex;
-    this.items.forEach(function(snippet, index) {
+
+    for (const [index, snippet] of this.items.entries()) {
       var flags = snippet.flags;
 
       switch (snippet.lang) {
@@ -36,7 +37,7 @@ class Snippets {
           }
           break;
       }
-    });
+    }
 
     return tests;
   }

lib/convertMarkdownToMocha.js

@@ -141,7 +141,7 @@ function findCodeBlocks(mdSrc) {
 function compileCodeBlocksToAst(codeBlocks, fileName) {
   var top = [];
   var cursor = top;
-  codeBlocks.forEach(function(codeBlock, i) {
+  for (const [i, codeBlock] of codeBlocks.entries()) {
     var previousExampleNumber = i + 1;
     var topLevelStatements = esprima.parse(
       `${new Array(codeBlock.lineNumber).join('\n')}(function () {\n${
@@ -150,7 +150,10 @@ function compileCodeBlocksToAst(codeBlocks, fileName) {
       { loc: true, source: pathModule.resolve(fileName) }
     ).body[0].expression.callee.body.body;
 
-    topLevelStatements.forEach(function(topLevelStatement, i) {
+    for (const [
+      statementIndex,
+      topLevelStatement
+    ] of topLevelStatements.entries()) {
       switch (topLevelStatement.type) {
         case 'VariableDeclaration':
           topLevelStatement.kind = 'var';
@@ -169,10 +172,10 @@ function compileCodeBlocksToAst(codeBlocks, fileName) {
             ],
             kind: 'var'
           };
-          topLevelStatements[i] = newStatement;
+          topLevelStatements[statementIndex] = newStatement;
           break;
       }
-    });
+    }
 
     if (codeBlock.flags.freshExpect) {
       Array.prototype.push.apply(
@@ -242,7 +245,7 @@ function compileCodeBlocksToAst(codeBlocks, fileName) {
       }
       Array.prototype.push.apply(cursor, check);
     }
-  });
+  }
   return top;
 }
 
@@ -297,8 +300,9 @@ module.exports = function(mdSrc, fileName) {
     );
 
     preamble = esprima.parse(transpiledBlocks[0]);
+    const remainingBlocks = transpiledBlocks.slice(1);
 
-    transpiledBlocks.slice(1).forEach(function(transpiledBlock, i) {
+    for (const [i, transpiledBlock] of remainingBlocks.entries()) {
       if (codeBlocks[i].flags.async) {
         codeBlocks[i].code = transpiledBlock
           .replace(/^\(function unexpectedMarkdownScope\(\) \{\n/, '')
@@ -307,10 +311,10 @@ module.exports = function(mdSrc, fileName) {
       } else {
         codeBlocks[i].code = transpiledBlock;
       }
-    });
+    }
   }
 
-  codeBlocks.forEach(function(codeBlock, i) {
+  for (const [i, codeBlock] of codeBlocks.entries()) {
     var exampleNumber = i + 1;
     /* eslint-disable */
     var itExpressionStatement = parseFunctionBody(function f() {
@@ -336,6 +340,6 @@ module.exports = function(mdSrc, fileName) {
       itExpressionStatement.expression.arguments[1].body.body,
       compileCodeBlocksToAst(codeBlocks.slice(0, i + 1), fileName)
     );
-  });
+  }
   return escodegen.generate(ast, { sourceMap: true, sourceMapWithCode: true });
 };

lib/evaluateSnippets.js

@@ -29,9 +29,9 @@ try {
 function extend(target) {
   for (var i = 1; i < arguments.length; i += 1) {
     var source = arguments[i];
-    Object.keys(source).forEach(function(key) {
+    for (const key of Object.keys(source)) {
       target[key] = source[key];
-    });
+    }
   }
   return target;
 }
@@ -96,11 +96,13 @@ module.exports = async function(snippets, options) {
       );
 
       var preamble = transpiledSnippets[0];
+      const remainingSnippets = transpiledSnippets.slice(1);
+
       vm.runInThisContext(preamble);
 
-      transpiledSnippets.slice(1).forEach(function(transpiledSnippet, i) {
+      for (const [i, transpiledSnippet] of remainingSnippets.entries()) {
         exampleSnippets[i].code = transpiledSnippet;
-      });
+      }
     }
   }
 
@@ -141,11 +143,11 @@ module.exports = async function(snippets, options) {
     }
   }
 
-  Object.keys(global).forEach(function(key) {
+  for (const key of Object.keys(global)) {
     if (!(key in oldGlobal)) {
       delete global[key];
     }
-  });
+  }
 
   // local function used for compatibility with node 8
   extend(global, oldGlobal);

lib/extractSnippets.js

@@ -2,10 +2,10 @@ var snippetRegexp = require('./snippetRegexp');
 
 function parseFlags(flagsString) {
   var flags = {};
-  flagsString.split(/,/).forEach(function(flagString) {
+  for (const flagString of flagsString.split(/,/)) {
     var m = /(\w+)\s*:\s*(\w+)/.exec(flagString.trim());
     flags[m[1]] = m[2] === 'true';
-  });
+  }
   return flags;
 }