Fall back to regex if babylon fails

davidmfoley · Sep 24, 2016 · 9a770c1 · 9a770c1
1 parent 86f5965
commit 9a770c1
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Showing 2 changed files with 57 additions and 2 deletions.
diff --git a/lib/analyzeFiles/findRequires/javascriptRequireFinder.js b/lib/analyzeFiles/findRequires/javascriptRequireFinder.js
@@ -3,6 +3,37 @@ var requirePathFilter = require('./requirePathFilter');
 
 module.exports = function(contents, filename) {
   contents = handleShebang(contents);
+  try {
+    return babylonFinder(contents);
+  }
+  catch (err) {
+    //fall back to stupid/fragile regex parsing
+    return regexFinder(contents);
+  }
+};
+
+function regexFinder(contents) {
+  var lines = contents.split('\n');
+  var requires = [];
+  var importRegex = /(import .+? from|require\s*\()\s*['"`]/g;
+  lines.map(function(line, i) {
+    var result = importRegex.exec(line);
+    if (!result) return;
+    var location = result.index + result[0].length;
+    var requirePath = line.substring(location).split(/['"`]/)[0];
+    requires.push({
+      path: requirePath,
+      loc: {
+        line: i,
+        start: location,
+        length: requirePath.length
+      }
+    });
+  });
+  return requires;
+}
+
+function babylonFinder(contents) {
 
   // kitchen-sink approach, since we just want to find requires/imports/etc.
   var bbl = babylon.parse(contents, {sourceType: 'module', plugins: [
@@ -24,12 +55,13 @@ module.exports = function(contents, filename) {
   var requires = [];
   scan(bbl.tokens, requires);
   return requires;
-};
+}
 
 function scan(tokens, requires, index) {
   for(var i = 0; i < tokens.length; i++) {
     var token = tokens[i];
-    if (token.type.keyword === 'import' || (token.type.label === 'name' && token.value === 'require')) {
+    var type = token.type;
+    if (type.keyword === 'import' || (type.label === 'name' && token.value === 'require')) {
       while ( tokens[i] && tokens[i].type && tokens[i].type.label !== 'string' && i < tokens.length) { i++; }
 
       addIfMatch(requires, tokens[i]);

diff --git a/test/findRequires_spec.js b/test/findRequires_spec.js
@@ -51,6 +51,8 @@ export const fetchLookup = query =>
       expect(requires[0].path).to.equal('./foo');
     });
 
+
+
   });
 
   describe('with javascript', () =>  {
@@ -65,6 +67,27 @@ export const fetchLookup = query =>
       expect(requires[0].path).to.equal('./foo');
     });
 
+    it('handles import in a file that babylon can\'t fully parse',  () =>  {
+      const code = `import * as x from './y';
+let foo;
+foo = foo || () => {}; //babylon can't handle this for some reason
+      `;
+      const requires = findRequires('js', code);
+      expect(requires.length).to.eql(1);
+      expect(requires[0].path).to.equal('./y');
+    });
+
+    it('handles require in a file that babylon can\'t fully parse',  () =>  {
+      const code = `const x = require('./y');
+let foo;
+foo = foo || () => {}; //babylon can't handle this for some reason
+      `;
+      const requires = findRequires('js', code);
+      expect(requires.length).to.eql(1);
+      expect(requires[0].path).to.equal('./y');
+    });
+
+
     it('handles a shebanged javascript file', () =>  {
       const code = "#! /usr/bin/env node\nvar foo = require( './foo' );\n";
       const requires = findRequires('js', code);