Fix a bug where $ sign in dart outputs would fail compilation (#2194)

Author: sobolk

.changeset/new-buckets-mix.md

@@ -0,0 +1,5 @@
+---
+'@aws-amplify/client-config': patch
+---
+
+Fix a bug where $ sign in dart outputs would fail compilation

packages/client-config/src/client-config-writer/client_config_formatter_default.test.ts

@@ -50,7 +50,7 @@ void describe('client config formatter', () => {
       ClientConfigFormat.DART
     );
 
-    assert.ok(formattedConfig.startsWith("const amplifyConfig = '''"));
+    assert.ok(formattedConfig.startsWith("const amplifyConfig = r'''"));
     assert.ok(
       formattedConfig.includes(JSON.stringify(expectedConfigReturned, null, 2))
     );

packages/client-config/src/client-config-writer/client_config_formatter_default.ts

@@ -16,7 +16,9 @@ export class ClientConfigFormatterDefault implements ClientConfigFormatter {
   format = (clientConfig: ClientConfig, format: ClientConfigFormat): string => {
     switch (format) {
       case ClientConfigFormat.DART: {
-        return `const amplifyConfig = '''${JSON.stringify(
+        // Using raw string, i.e. r''' to disable Dart's interpolations
+        // because we're using special characters like $ in some outputs.
+        return `const amplifyConfig = r'''${JSON.stringify(
           clientConfig,
           null,
           2

packages/client-config/src/client-config-writer/client_config_formatter_legacy.test.ts

@@ -109,7 +109,7 @@ void describe('client config formatter', () => {
       expectedLegacyConfig.aws_user_pools_id
     );
 
-    assert.ok(formattedConfig.startsWith("const amplifyConfig = '''"));
+    assert.ok(formattedConfig.startsWith("const amplifyConfig = r'''"));
     assert.ok(
       formattedConfig.includes(JSON.stringify(clientConfigMobile, null, 2))
     );

packages/client-config/src/client-config-writer/client_config_formatter_legacy.ts

@@ -29,7 +29,9 @@ export class ClientConfigFormatterLegacy implements ClientConfigFormatter {
         }export default amplifyConfig;${os.EOL}`;
       }
       case ClientConfigFormat.DART: {
-        return `const amplifyConfig = '''${JSON.stringify(
+        // Using raw string, i.e. r''' to disable Dart's interpolations
+        // because we're using special characters like $ in some outputs.
+        return `const amplifyConfig = r'''${JSON.stringify(
           this.configConverter.convertToMobileConfig(legacyConfig),
           null,
           2