warn/error based on function.json files

Azure · Sep 28, 2022 · e8db8a0 · e8db8a0
1 parent 3f99a71
commit e8db8a0
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Showing 2 changed files with 101 additions and 7 deletions.
diff --git a/src/startApp.ts b/src/startApp.ts
@@ -64,11 +64,45 @@ async function loadEntryPointFile(functionAppDirectory: string, channel: WorkerC
             }
         } catch (err) {
             const error = ensureErrorType(err);
-            channel.log({
-                message: `Worker was unable to load entry point "${entryPointPattern}": ${error.message}`,
-                level: LogLevel.Warning,
-                logCategory: LogCategory.System,
-            });
+            const message = `Worker was unable to load entry point "${entryPointPattern}": ${error.message}`;
+
+            // If this is an old existing app, we can't throw an error about the entrypoint for backwards compat reasons
+            // More info here: https://github.com/Azure/azure-functions-nodejs-worker/issues/630
+            // However, if we determine this is the new programming model, we will do the "proper" thing and throw an error
+            if (await isNewProgrammingModel(functionAppDirectory)) {
+                channel.log({
+                    message:
+                        'No "function.json" files found, so assuming this app uses a programming model requiring a valid "main" field in "package.json".',
+                    level: LogLevel.Warning,
+                    logCategory: LogCategory.System,
+                });
+
+                error.isAzureFunctionsSystemError = true;
+                error.message = message;
+                throw error;
+            } else {
+                channel.log({
+                    message,
+                    level: LogLevel.Warning,
+                    logCategory: LogCategory.System,
+                });
+            }
         }
     }
 }
+
+/**
+ * Best effort to determine if this is the new programming model based on the existence of "function.json" files
+ * Defaults to false if we can't figure it out
+ */
+async function isNewProgrammingModel(functionAppDirectory: string): Promise<boolean> {
+    try {
+        const files = await globby('*/function.json', {
+            cwd: functionAppDirectory,
+            caseSensitiveMatch: false,
+        });
+        return files.length === 0;
+    } catch {
+        return false;
+    }
+}
diff --git a/test/eventHandlers/WorkerInitHandler.test.ts b/test/eventHandlers/WorkerInitHandler.test.ts
@@ -137,6 +137,15 @@ export namespace Msg {
             logCategory: LogCategory.System,
         },
     };
+
+    export const noFunctionJsonWarning: rpc.IStreamingMessage = {
+        rpcLog: {
+            message:
+                'No "function.json" files found, so assuming this app uses a programming model requiring a valid "main" field in "package.json".',
+            level: LogLevel.Warning,
+            logCategory: LogCategory.System,
+        },
+    };
 }
 
 describe('WorkerInitHandler', () => {
@@ -283,13 +292,16 @@ describe('WorkerInitHandler', () => {
         );
     });
 
-    it('Fails for missing entry point', async function (this: ITestCallbackContext) {
+    it('Warns for missing entry point in old programming model', async function (this: ITestCallbackContext) {
         const fileName = 'entryPointFiles/missing.js';
         const expectedPackageJson = {
             main: fileName,
         };
         mockFs({
             [__dirname]: {
+                HttpTrigger1: {
+                    'function.json': '{}',
+                },
                 'package.json': JSON.stringify(expectedPackageJson),
             },
         });
@@ -299,13 +311,16 @@ describe('WorkerInitHandler', () => {
         await stream.assertCalledWith(Msg.receivedInitLog, Msg.warning(warningMessage), Msg.response);
     });
 
-    it('Fails for invalid entry point', async function (this: ITestCallbackContext) {
+    it('Warns for invalid entry point in old programming model', async function (this: ITestCallbackContext) {
         const fileName = 'entryPointFiles/throwError.js';
         const expectedPackageJson = {
             main: fileName,
         };
         mockFs({
             [__dirname]: {
+                HttpTrigger1: {
+                    'fuNcTion.json': '{}', // try different casing as well
+                },
                 'package.json': JSON.stringify(expectedPackageJson),
                 // 'require' and 'mockFs' don't play well together so we need these files in both the mock and real file systems
                 entryPointFiles: mockFs.load(path.join(__dirname, 'entryPointFiles')),
@@ -321,4 +336,49 @@ describe('WorkerInitHandler', () => {
             Msg.response
         );
     });
+
+    it('Fails for missing entry point in new programming model', async () => {
+        const fileName = 'entryPointFiles/missing.js';
+        const expectedPackageJson = {
+            main: fileName,
+        };
+        mockFs({
+            [__dirname]: {
+                'package.json': JSON.stringify(expectedPackageJson),
+            },
+        });
+
+        stream.addTestMessage(Msg.init(__dirname));
+        const errorMessage = `Worker was unable to load entry point "${fileName}": Found zero files matching the supplied pattern`;
+        await stream.assertCalledWith(
+            Msg.receivedInitLog,
+            Msg.noFunctionJsonWarning,
+            Msg.error(errorMessage),
+            Msg.failedResponse(fileName, errorMessage)
+        );
+    });
+
+    it('Fails for invalid entry point in new programming model', async () => {
+        const fileName = 'entryPointFiles/throwError.js';
+        const expectedPackageJson = {
+            main: fileName,
+        };
+        mockFs({
+            [__dirname]: {
+                'package.json': JSON.stringify(expectedPackageJson),
+                // 'require' and 'mockFs' don't play well together so we need these files in both the mock and real file systems
+                entryPointFiles: mockFs.load(path.join(__dirname, 'entryPointFiles')),
+            },
+        });
+
+        stream.addTestMessage(Msg.init(__dirname));
+        const errorMessage = `Worker was unable to load entry point "${fileName}": test`;
+        await stream.assertCalledWith(
+            Msg.receivedInitLog,
+            Msg.loadingEntryPoint(fileName),
+            Msg.noFunctionJsonWarning,
+            Msg.error(errorMessage),
+            Msg.failedResponse(fileName, errorMessage)
+        );
+    });
 });