fix: create copies of original files prior to patching

This is needed as we revert patches when re-patching an already patched file
Mattlk13 · Mar 31, 2019 · 7fc32ca · 7fc32ca
1 parent ea33dc6
commit 7fc32ca
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Showing 3 changed files with 26 additions and 16 deletions.
diff --git a/src/lib/protect/apply-patch.js b/src/lib/protect/apply-patch.js
@@ -8,7 +8,7 @@ var fs = require('fs');
 var uuid = require('uuid/v4');
 var errorAnalytics = require('../analytics').single;
 
-function applyPatch(patch, vuln, live, patchUrl) {
+function applyPatch(patchFileName, vuln, live, patchUrl) {
   var cwd = vuln.source;
 
   return new Promise(function (resolve, reject) {
@@ -27,7 +27,7 @@ function applyPatch(patch, vuln, live, patchUrl) {
       debug('Failed loading package.json of package about to be patched', err);
     }
 
-    var patchContent = fs.readFileSync(path.resolve(relative, patch), 'utf8');
+    var patchContent = fs.readFileSync(path.resolve(relative, patchFileName), 'utf8');
 
     jsDiff(patchContent, relative, live).then(function () {
       debug('patch succeed');
@@ -49,7 +49,15 @@ function jsDiff(patchContent, relative, live) {
           if (patchedFiles[fileName]) {
             return callback(null, patchedFiles[fileName]);
           }
-          var content = fs.readFileSync(path.resolve(relative, fileName), 'utf8');
+
+          var filePath = path.resolve(relative, fileName);
+          var content = fs.readFileSync(filePath, 'utf8');
+
+          // create an `.orig` copy of the file prior to patching it
+          // used in case we need to revert a patch
+          var origFilePath = filePath + '.orig';
+          fs.writeFileSync(origFilePath, content);
+
           callback(null, content);
         } catch (err) {
           // collect patch metadata for error analysis
@@ -92,7 +100,7 @@ function jsDiff(patchContent, relative, live) {
         }
         try {
           // write patched files back to disk, unlink files completely removed by patching
-          for (var fileName of patchedFiles) {
+          for (var fileName in patchedFiles) {
             if (typeof patchedFiles[fileName] === 'string') {
               fs.writeFileSync(path.resolve(relative, fileName), patchedFiles[fileName]);
             } else {

diff --git a/src/lib/protect/patch.js b/src/lib/protect/patch.js
@@ -72,15 +72,17 @@ function patch(vulns, live) {
                     return reject(error);
                   }
 
-                  resolve(Promise.all(files.filter(function (file) {
+                  var origFiles = files.filter(function (file) {
                     return file.slice(-5) === '.orig';
-                  }).map(function (file) {
-                    return fs.rename(file, path.dirname(file) + '/' +
+                  });
+
+                  for (var file of origFiles) {
+                    fs.renameSync(file, path.dirname(file) + '/' +
                       path.basename(file).slice(0, -5));
-                  })));
+                  }
+
+                  resolve(patch);
                 });
-              }).then(function () {
-                return patch;
               });
             });
           }).then(function (patch) {

diff --git a/test/protect-apply-same-patch-again.test.js b/test/protect-apply-same-patch-again.test.js
@@ -32,8 +32,8 @@ const patch = proxyquire('../src/lib/protect/patch', {
 });
 
 test('setup', (t) => {
-  fs.createReadStream(fixturesModuleFolder + '/node-fixture.js')
-  .pipe(fs.createWriteStream(fixturesModuleFolder + '/node.js'));
+  var fixture = fs.readFileSync(fixturesModuleFolder + '/node-fixture.js');
+  fs.writeFileSync(fixturesModuleFolder + '/node.js', fixture);
   t.pass();
   t.end();
 });
@@ -44,13 +44,13 @@ test('Same patch is applied multiple times without issue', (t) => {
     fs.readdir(fixturesBaseFolder, (err, fileNames) => {
       const fixturesBaseFolderFiles = fileNames || [];
 
-      if (err || fixturesBaseFolderFiles.length == 0) {
+      if (err || fixturesBaseFolderFiles.length === 0) {
         console.log(`ERROR: Could not remove the .snyk-***.flag | ${err}`);
         return;
       }
 
       fixturesBaseFolderFiles.forEach((file) => {
-        const flagMatch = file.match(/\.snyk.*\.flag/)
+        const flagMatch = file.match(/\.snyk.*\.flag/);
         if (flagMatch) {
           fs.unlink(fixturesBaseFolder + file);
         }
@@ -60,7 +60,7 @@ test('Same patch is applied multiple times without issue', (t) => {
     fs.readdir(fixturesModuleFolder, (err, fileNames) => {
       const fixturesModuleFolderFiles = fileNames || [];
 
-      if (err || fixturesModuleFolderFiles.length == 0) {
+      if (err || fixturesModuleFolderFiles.length === 0) {
         return;
       }
 
@@ -100,5 +100,5 @@ test('Same patch is applied multiple times without issue', (t) => {
       t.pass();
       t.end();
     })
-    .catch(t.threw);
+    .catch(t.fail);
 });