From 998ccf6620f35cd9a576350fb004bf7884e7ef19 Mon Sep 17 00:00:00 2001
From: MT Lewis <mtlewis@users.noreply.github.com>
Date: Wed, 31 Jan 2024 10:47:22 +0000
Subject: [PATCH] app-backend: replace all instances when injecting config

Signed-off-by: MT Lewis <mtlewis@users.noreply.github.com>
---
 .changeset/red-eggs-serve.md               |  5 ++
 plugins/app-backend/src/lib/config.test.ts | 73 ++++++++++++++++++++++
 plugins/app-backend/src/lib/config.ts      |  6 +-
 3 files changed, 81 insertions(+), 3 deletions(-)
 create mode 100644 .changeset/red-eggs-serve.md

diff --git a/.changeset/red-eggs-serve.md b/.changeset/red-eggs-serve.md
new file mode 100644
index 0000000000..1b2c9b3b07
--- /dev/null
+++ b/.changeset/red-eggs-serve.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-app-backend': patch
+---
+
+Support injecting config multiple times in a single bundle
diff --git a/plugins/app-backend/src/lib/config.test.ts b/plugins/app-backend/src/lib/config.test.ts
index f36052116a..ed2b8b8777 100644
--- a/plugins/app-backend/src/lib/config.test.ts
+++ b/plugins/app-backend/src/lib/config.test.ts
@@ -62,6 +62,28 @@ describe('injectConfig', () => {
     expect(JSON.parse(eval(fsMock.writeFile.mock.calls[0][1]))).toEqual([]);
   });
 
+  it('should inject config repeatedly if marker appears multiple times', async () => {
+    fsMock.readdir.mockResolvedValue(['main.js'] as any);
+    readFileMock.mockImplementation(
+      async () =>
+        '({a:"__APP_INJECTED_RUNTIME_CONFIG__",b:"__APP_INJECTED_RUNTIME_CONFIG__"})',
+    );
+    await injectConfig(baseOptions);
+    expect(fsMock.readdir).toHaveBeenCalledTimes(1);
+    expect(fsMock.readFile).toHaveBeenCalledTimes(1);
+    expect(fsMock.writeFile).toHaveBeenCalledTimes(1);
+    expect(fsMock.writeFile).toHaveBeenCalledWith(
+      resolvePath(MOCK_DIR, 'main.js'),
+      '({a:/*__APP_INJECTED_CONFIG_MARKER__*/"[]"/*__INJECTED_END__*/,b:/*__APP_INJECTED_CONFIG_MARKER__*/"[]"/*__INJECTED_END__*/})',
+      'utf8',
+    );
+
+    // eslint-disable-next-line no-eval
+    expect(JSON.parse(eval(fsMock.writeFile.mock.calls[0][1]).a)).toEqual([]);
+    // eslint-disable-next-line no-eval
+    expect(JSON.parse(eval(fsMock.writeFile.mock.calls[0][1]).b)).toEqual([]);
+  });
+
   it('should find the correct file to inject', async () => {
     fsMock.readdir.mockResolvedValue([
       'before.js',
@@ -152,4 +174,55 @@ describe('injectConfig', () => {
       { data: { x: 1, y: 2 }, context: 'test' },
     ]);
   });
+
+  it('should re-inject config repeatedly if needed', async () => {
+    fsMock.readdir.mockResolvedValue(['main.js'] as any);
+    readFileMock.mockResolvedValue(
+      '({ a: JSON.parse("__APP_INJECTED_RUNTIME_CONFIG__"), b: JSON.parse("__APP_INJECTED_RUNTIME_CONFIG__") })',
+    );
+
+    await injectConfig({
+      ...baseOptions,
+      appConfigs: [{ data: { x: 0 }, context: 'test' }],
+    });
+
+    expect(fsMock.writeFile).toHaveBeenCalledTimes(1);
+    expect(fsMock.writeFile).toHaveBeenCalledWith(
+      resolvePath(MOCK_DIR, 'main.js'),
+      '({ a: JSON.parse(/*__APP_INJECTED_CONFIG_MARKER__*/"[{\\"data\\":{\\"x\\":0},\\"context\\":\\"test\\"}]"/*__INJECTED_END__*/), b: JSON.parse(/*__APP_INJECTED_CONFIG_MARKER__*/"[{\\"data\\":{\\"x\\":0},\\"context\\":\\"test\\"}]"/*__INJECTED_END__*/) })',
+      'utf8',
+    );
+
+    // eslint-disable-next-line no-eval
+    expect(eval(fsMock.writeFile.mock.calls[0][1]).a).toEqual([
+      { data: { x: 0 }, context: 'test' },
+    ]);
+    // eslint-disable-next-line no-eval
+    expect(eval(fsMock.writeFile.mock.calls[0][1]).b).toEqual([
+      { data: { x: 0 }, context: 'test' },
+    ]);
+
+    readFileMock.mockResolvedValue(fsMock.writeFile.mock.calls[0][1]);
+
+    await injectConfig({
+      ...baseOptions,
+      appConfigs: [{ data: { x: 1, y: 2 }, context: 'test' }],
+    });
+
+    expect(fsMock.writeFile).toHaveBeenCalledTimes(2);
+    expect(fsMock.writeFile).toHaveBeenLastCalledWith(
+      resolvePath(MOCK_DIR, 'main.js'),
+      '({ a: JSON.parse(/*__APP_INJECTED_CONFIG_MARKER__*/"[{\\"data\\":{\\"x\\":1,\\"y\\":2},\\"context\\":\\"test\\"}]"/*__INJECTED_END__*/), b: JSON.parse(/*__APP_INJECTED_CONFIG_MARKER__*/"[{\\"data\\":{\\"x\\":1,\\"y\\":2},\\"context\\":\\"test\\"}]"/*__INJECTED_END__*/) })',
+      'utf8',
+    );
+
+    // eslint-disable-next-line no-eval
+    expect(eval(fsMock.writeFile.mock.calls[1][1]).a).toEqual([
+      { data: { x: 1, y: 2 }, context: 'test' },
+    ]);
+    // eslint-disable-next-line no-eval
+    expect(eval(fsMock.writeFile.mock.calls[1][1]).b).toEqual([
+      { data: { x: 1, y: 2 }, context: 'test' },
+    ]);
+  });
 });
diff --git a/plugins/app-backend/src/lib/config.ts b/plugins/app-backend/src/lib/config.ts
index 05b304075e..63912df5c4 100644
--- a/plugins/app-backend/src/lib/config.ts
+++ b/plugins/app-backend/src/lib/config.ts
@@ -49,7 +49,7 @@ export async function injectConfig(
     if (content.includes('__APP_INJECTED_RUNTIME_CONFIG__')) {
       logger.info(`Injecting env config into ${jsFile}`);
 
-      const newContent = content.replace(
+      const newContent = content.replaceAll(
         '"__APP_INJECTED_RUNTIME_CONFIG__"',
         injected,
       );
@@ -58,8 +58,8 @@ export async function injectConfig(
     } else if (content.includes('__APP_INJECTED_CONFIG_MARKER__')) {
       logger.info(`Replacing injected env config in ${jsFile}`);
 
-      const newContent = content.replace(
-        /\/\*__APP_INJECTED_CONFIG_MARKER__\*\/.*\/\*__INJECTED_END__\*\//,
+      const newContent = content.replaceAll(
+        /\/\*__APP_INJECTED_CONFIG_MARKER__\*\/.*?\/\*__INJECTED_END__\*\//g,
         injected,
       );
       await fs.writeFile(path, newContent, 'utf8');