fix(jsii): unexpected deprecated warnings when a deprecated interface…

… is extended

It is common in the AWS CDK for non-deprecated interfaces to extend
deprecated interfaces.
Currently, when this occurs and the non-deprecated subclass is
referenced, a warning is generated notifying the deprecation of its
superclass.

Modify the implementation such that the warning is produced only when
a property of the deprecated interface is referenced.

In the case when a deprecated interface with no required properties is
used without any of its properties set, a warning will not be generated.
This should occur rarely and the trade off is acceptable.

fixes #3111

packages/jsii/lib/transforms/deprecation-warnings.ts

@@ -42,10 +42,7 @@ export class DeprecationWarningsInjector {
         ),
       );
 
-      if (
-        spec.isDeprecated(type) &&
-        (spec.isEnumType(type) || (spec.isInterfaceType(type) && type.datatype))
-      ) {
+      if (spec.isDeprecated(type) && spec.isEnumType(type)) {
         // The type is deprecated
         statements.push(
           createWarningFunctionCall(type.fqn, type.docs?.deprecated),
@@ -78,12 +75,14 @@ export class DeprecationWarningsInjector {
         }
       } else if (spec.isInterfaceType(type) && type.datatype) {
         for (const prop of Object.values(type.properties ?? {})) {
-          if (spec.isDeprecated(prop)) {
-            // The property is deprecated
+          if (spec.isDeprecated(prop) || spec.isDeprecated(type)) {
+            // If the property individually is deprecated, or the entire type is deprecated
+            const deprecatedDocs =
+              prop.docs?.deprecated ?? type.docs?.deprecated;
             statements.push(
               createWarningFunctionCall(
                 `${type.fqn}#${prop.name}`,
-                prop.docs?.deprecated,
+                deprecatedDocs,
                 ts.createIdentifier(`"${prop.name}" in ${PARAMETER_NAME}`),
               ),
             );

packages/jsii/test/deprecation-warnings.test.ts

@@ -266,6 +266,29 @@ function testpkg_Baz(p) {
 `);
   });
 
+  test('generates calls for deprecated interface', async () => {
+    const result = await compileJsiiForTest(
+      `
+      /** @deprecated use Bar instead */
+      export interface Foo {
+        readonly bar: string;
+      }
+      `,
+      undefined /* callback */,
+      { addDeprecationWarnings: true },
+    );
+
+    expect(jsFile(result, '.warnings.jsii')).toMatch(`function testpkg_Foo(p) {
+    if (p == null)
+        return;
+    visitedObjects.add(p);
+    if ("bar" in p)
+        print("testpkg.Foo#bar", "use Bar instead");
+    visitedObjects.delete(p);
+}
+`);
+  });
+
   test('generates calls for types in other assemblies', async () => {
     const calcBaseRoot = resolveModuleDir('@scope/jsii-calc-base');
     const calcLibRoot = resolveModuleDir('@scope/jsii-calc-lib');