Always use base64 encoding to prevent interpreting binary files as utf-8 text files

Signed-off-by: Kenneth Feng <kenneth.feng@onepeloton.com>

plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/githubPullRequest.test.ts

@@ -99,8 +99,8 @@ describe('createPublishGithubPullRequestAction', () => {
             commit: 'Create my new app',
             files: {
               'file.txt': {
-                encoding: 'utf-8',
-                content: 'Hello there!',
+                content: Buffer.from('Hello there!').toString('base64'),
+                encoding: 'base64',
                 mode: '100644',
               },
             },
@@ -172,8 +172,8 @@ describe('createPublishGithubPullRequestAction', () => {
             commit: 'Create my new app',
             files: {
               'foo.txt': {
-                content: 'Hello there!',
-                encoding: 'utf-8',
+                content: Buffer.from('Hello there!').toString('base64'),
+                encoding: 'base64',
                 mode: '100644',
               },
             },
@@ -230,8 +230,8 @@ describe('createPublishGithubPullRequestAction', () => {
             commit: 'Create my new app',
             files: {
               'file.txt': {
-                content: 'Hello there!',
-                encoding: 'utf-8',
+                content: Buffer.from('Hello there!').toString('base64'),
+                encoding: 'base64',
                 mode: '100644',
               },
             },
@@ -298,8 +298,8 @@ describe('createPublishGithubPullRequestAction', () => {
             commit: 'Create my new app',
             files: {
               'file.txt': {
-                content: 'Hello there!',
-                encoding: 'utf-8',
+                content: Buffer.from('Hello there!').toString('base64'),
+                encoding: 'base64',
                 mode: '100755',
               },
             },

plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/githubPullRequest.ts

@@ -196,15 +196,23 @@ export const createPublishGithubPullRequestAction = ({
       const fileContents = await Promise.all(
         localFilePaths.map(filePath => {
           const absPath = path.resolve(fileRoot, filePath);
-          const content = fs.readFileSync(absPath).toString();
+          const base64EncodedContent = fs
+            .readFileSync(absPath)
+            .toString('base64');
           const fileStat = fs.statSync(absPath);
           const isExecutable = fileStat.mode === 33277; // aka. 100755
           // See the properties of tree items
           // in https://docs.github.com/en/rest/reference/git#trees
           const githubTreeItemMode = isExecutable ? '100755' : '100644';
+          // Always use base64 encoding to avoid doubling a binary file in size
+          // due to interpreting a binary file as utf-8 and sending github
+          // the utf-8 encoded content.
+          //
+          // For example, the original gradle-wrapper.jar is 57.8k in https://github.com/kennethzfeng/pull-request-test/pull/5/files.
+          // Its size could be doubled to 98.3K (See https://github.com/kennethzfeng/pull-request-test/pull/4/files)
           return {
-            encoding: 'utf-8',
-            content: content,
+            encoding: 'base64',
+            content: base64EncodedContent,
             mode: githubTreeItemMode,
           };
         }),