fix(cli): retain type of context values and not convert them to string (#595)

Fixes [#30583](aws/aws-cdk#30583)

CLI’s context-passing mechanism relied on serialising every entry to a
"KEY=VALUE" string, leading CLI to only allows passing string context,
so even JSON booleans (true/false) and numbers became plain strings.
This resulted in losing the typed context, like boolean feature-flags
are always being passed as string "true"/"false". This incorrectly
passed feature flags caused certain integration tests snapshot in the
[aws-cdk](https://github.com/aws/aws-cdk/tree/main/packages/%40aws-cdk-testing/framework-integ)
library to be updated with incorrect values causing the integration
tests to fail.

This fix retains the type of context values when passed via CLI, by
correctly JSON parsing the context while building user configuration.
Values that aren’t valid JSON will fall back to plain strings, so
existing workflows should continue working as is. This will restore
correct typing for feature flags without disrupting existing tests.

---
By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license

---------

Co-authored-by: Momo Kornher <[email protected]>

Author: kumsmrit

packages/@aws-cdk-testing/cli-integ/resources/cdk-apps/app/app.js

@@ -453,7 +453,8 @@ class LambdaStack extends cdk.Stack {
   constructor(parent, id, props) {
     // sometimes we need to specify the custom bootstrap bucket to use
     // see the 'upgrade legacy bootstrap stack' test
-    const synthesizer = parent.node.tryGetContext('legacySynth') === 'true' ?
+    const useLegacy = [true, 'true'].includes(parent.node.tryGetContext('legacySynth'));
+    const synthesizer = useLegacy ?
       new LegacyStackSynthesizer({
         fileAssetsBucketName: parent.node.tryGetContext('bootstrapBucket'),
       })
@@ -477,7 +478,8 @@ class LambdaStack extends cdk.Stack {
 
 class DriftableStack extends cdk.Stack {
   constructor(parent, id, props) {
-    const synthesizer = parent.node.tryGetContext('legacySynth') === 'true' ?
+    const useLegacy = [true, 'true'].includes(parent.node.tryGetContext('legacySynth'));
+    const synthesizer = useLegacy ?
       new LegacyStackSynthesizer({
         fileAssetsBucketName: parent.node.tryGetContext('bootstrapBucket'),
       })

packages/aws-cdk/lib/cli/user-configuration.ts

@@ -341,7 +341,13 @@ function parseStringContextListToObject(argv: Arguments): any {
           `User-provided context cannot use keys prefixed with 'aws:', but ${parts[0]} was provided.`,
         );
       }
-      context[parts[0]] = parts[1];
+      let parsedValue: any = parts[1];
+      try {
+        parsedValue = JSON.parse(parts[1]);
+      } catch {
+        debug('Non-JSON context value for %s, leaving as string: %s', parts[0], parts[1]);
+      }
+      context[parts[0]] = parsedValue;
     } else {
       warning(
         'Context argument is not an assignment (key=value): %s',

packages/aws-cdk/test/cli/configuration.test.ts

@@ -116,3 +116,23 @@ test('providing a build arg', () => {
   // THEN
   expect(settings.get(['build'])).toEqual('mvn package');
 });
+
+test('can parse boolean context from command line arguments', () => {
+  // GIVEN
+  const settings1 = commandLineArgumentsToSettings({ context: ['foo=true'], _: [Command.DEPLOY] });
+  const settings2 = commandLineArgumentsToSettings({ context: ['foo=false'], _: [Command.DEPLOY] });
+
+  // THEN
+  expect(settings1.get(['context']).foo).toEqual( true );
+  expect(settings2.get(['context']).foo).toEqual( false );
+});
+
+test('can parse number context from command line arguments', () => {
+  // GIVEN
+  const settings1 = commandLineArgumentsToSettings({ context: ['foo=5'], _: [Command.DEPLOY] });
+  const settings2 = commandLineArgumentsToSettings({ context: ['foo=3.14'], _: [Command.DEPLOY] });
+
+  // THEN
+  expect(settings1.get(['context']).foo).toEqual( 5 );
+  expect(settings2.get(['context']).foo).toEqual( 3.14 );
+});