Handle schema errors

.changeset/spicy-toys-scream.md

@@ -0,0 +1,5 @@
+---
+'@aws-amplify/schema-generator': patch
+---
+
+Handle schema errors

packages/schema-generator/src/generate_schema.test.ts

@@ -2,10 +2,13 @@ import { beforeEach, describe, it, mock } from 'node:test';
 import { SchemaGenerator, parseDatabaseUrl } from './generate_schema.js';
 import assert from 'node:assert';
 import {
+  EmptySchemaError,
+  InvalidSchemaError,
   TypescriptDataSchemaGenerator,
   TypescriptDataSchemaGeneratorConfig,
 } from '@aws-amplify/graphql-schema-generator';
 import fs from 'fs/promises';
+import { AmplifyUserError } from '@aws-amplify/platform-core';
 
 const mockGenerateMethod =
   mock.fn<(config: TypescriptDataSchemaGeneratorConfig) => Promise<string>>();
@@ -164,4 +167,53 @@ void describe('SchemaGenerator', () => {
         'Unable to parse the database URL. Unsupported database engine: incorrect',
     });
   });
+
+  void it('should throw error if database schema is incorrect', async () => {
+    mockGenerateMethod.mock.mockImplementationOnce(() => {
+      throw new InvalidSchemaError([{}], ['missingColumn']);
+    });
+    const schemaGenerator = new SchemaGenerator();
+    await assert.rejects(
+      () =>
+        schemaGenerator.generate({
+          connectionUri: {
+            secretName: 'FAKE_SECRET_NAME',
+            value: 'mysql://user:password@hostname:3306/db',
+          },
+          out: 'schema.ts',
+        }),
+      (error: AmplifyUserError) => {
+        assert.strictEqual(error.name, 'DatabaseSchemaError');
+        assert.strictEqual(
+          error.message,
+          'Imported SQL schema is invalid. Imported schema is missing columns: missingColumn'
+        );
+        assert.strictEqual(error.resolution, 'Check the database schema.');
+        return true;
+      }
+    );
+  });
+
+  void it('should throw error if database schema is empty', async () => {
+    mockGenerateMethod.mock.mockImplementationOnce(() => {
+      throw new EmptySchemaError();
+    });
+    const schemaGenerator = new SchemaGenerator();
+    await assert.rejects(
+      () =>
+        schemaGenerator.generate({
+          connectionUri: {
+            secretName: 'FAKE_SECRET_NAME',
+            value: 'mysql://user:password@hostname:3306/db',
+          },
+          out: 'schema.ts',
+        }),
+      (error: AmplifyUserError) => {
+        assert.strictEqual(error.name, 'DatabaseSchemaError');
+        assert.strictEqual(error.message, 'Imported SQL schema is empty.');
+        assert.strictEqual(error.resolution, 'Check the database schema.');
+        return true;
+      }
+    );
+  });
 });

packages/schema-generator/src/generate_schema.ts

@@ -1,4 +1,8 @@
-import { TypescriptDataSchemaGenerator } from '@aws-amplify/graphql-schema-generator';
+import {
+  EmptySchemaError,
+  InvalidSchemaError,
+  TypescriptDataSchemaGenerator,
+} from '@aws-amplify/graphql-schema-generator';
 import fs from 'fs/promises';
 import { AmplifyUserError } from '@aws-amplify/platform-core';
 
@@ -16,6 +20,7 @@ export type SchemaGeneratorConfig = {
 
 type AmplifyGenerateSchemaError =
   | 'DatabaseConnectionError'
+  | 'DatabaseSchemaError'
   | 'DatabaseUnsupportedEngineError'
   | 'DatabaseUrlParseError';
 
@@ -38,6 +43,20 @@ export class SchemaGenerator {
       });
       await fs.writeFile(props.out, schema);
     } catch (err) {
+      if (
+        err instanceof EmptySchemaError ||
+        err instanceof InvalidSchemaError
+      ) {
+        throw new AmplifyUserError<AmplifyGenerateSchemaError>(
+          'DatabaseSchemaError',
+          {
+            // the message already contains descriptive error.
+            message: err.message,
+            resolution: 'Check the database schema.',
+          },
+          err
+        );
+      }
       const databaseError = err as DatabaseConnectError;
       if (databaseError.code === 'ETIMEDOUT') {
         throw new AmplifyUserError<AmplifyGenerateSchemaError>(