fix: correct waiters with broken subfield projections (#846)

Author: lucix-aws

.changes/3cf671d8-1ec4-4e2f-a4ae-0f1f08f73fd1.json

@@ -0,0 +1,5 @@
+{
+    "id": "3cf671d8-1ec4-4e2f-a4ae-0f1f08f73fd1",
+    "type": "bugfix",
+    "description": "Fix broken shape cursor when generating acceptor subfield projections."
+}

codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/KotlinJmespathExpressionVisitor.kt

@@ -90,8 +90,8 @@ class KotlinJmespathExpressionVisitor(
         if (!condition) throw CodegenException(lazyMessage())
     }
 
-    private fun flatMappingBlock(right: JmespathExpression, leftName: String, leftShape: Shape): String {
-        if (right is CurrentExpression) return leftName // Nothing to map
+    private fun flatMappingBlock(right: JmespathExpression, leftName: String, leftShape: Shape): VisitedExpression {
+        if (right is CurrentExpression) return VisitedExpression(leftName, leftShape) // nothing to map
 
         val outerName = bestTempVarName("projection")
         writer.openBlock("val #L = #L.flatMap {", outerName, leftName)
@@ -104,7 +104,7 @@ class KotlinJmespathExpressionVisitor(
         writer.write(innerCollector)
 
         writer.closeBlock("}")
-        return outerName
+        return VisitedExpression(outerName, innerResult.shape)
     }
 
     private fun subfield(expression: FieldExpression, parentName: String): VisitedExpression {
@@ -187,8 +187,7 @@ class KotlinJmespathExpressionVisitor(
             write("#L == true", comparison.identifier)
         }
 
-        val ident = flatMappingBlock(expression.right, filteredName, left.shape)
-        return VisitedExpression(ident, left.shape)
+        return flatMappingBlock(expression.right, filteredName, left.shape)
     }
 
     override fun visitFlatten(expression: FlattenExpression): VisitedExpression {
@@ -279,8 +278,7 @@ class KotlinJmespathExpressionVisitor(
         val valuesExpr = ensureNullGuard(left.shape, "values")
         val valuesName = addTempVar("${left.identifier}Values", "${left.identifier}$valuesExpr")
 
-        val ident = flatMappingBlock(expression.right, valuesName, left.shape)
-        return VisitedExpression(ident, left.shape)
+        return flatMappingBlock(expression.right, valuesName, left.shape)
     }
 
     override fun visitOr(expression: OrExpression): VisitedExpression {
@@ -299,8 +297,7 @@ class KotlinJmespathExpressionVisitor(
         val left = acceptSubexpression(expression.left)
         requireNotNull(left.shape) { "projection is operating on nothing?" }
 
-        val ident = flatMappingBlock(expression.right, left.identifier, left.shape)
-        return VisitedExpression(ident, left.shape)
+        return flatMappingBlock(expression.right, left.identifier, left.shape)
     }
 
     override fun visitSlice(expression: SliceExpression): VisitedExpression {

tests/codegen/waiter-tests/model/waiter-operations.smithy

@@ -699,6 +699,36 @@ service WaitersTestService {
             }
         ]
     },
+
+    // subfield projection
+    HasStructWithStringByProjection: {
+        acceptors: [
+            {
+                state: "success",
+                matcher: {
+                    output: {
+                        path: "lists.structs[].primitives.string"
+                        expected: "foo",
+                        comparator: "anyStringEquals"
+                    }
+                }
+            }
+        ]
+    },
+    HasStructWithSubstructWithStringByProjection: {
+        acceptors: [
+            {
+                state: "success",
+                matcher: {
+                    output: {
+                        path: "lists.structs[].subStructs[].subStructPrimitives.string"
+                        expected: "foo",
+                        comparator: "anyStringEquals"
+                    }
+                }
+            }
+        ]
+    },
 )
 @readonly
 @http(method: "GET", uri: "/entities/{name}", code: 200)
@@ -833,4 +863,13 @@ structure Struct {
     primitives: EntityPrimitives,
     strings: StringList,
     enums: EnumList,
+    subStructs: SubStructList,
+}
+
+list SubStructList {
+    member: SubStruct,
+}
+
+structure SubStruct {
+    subStructPrimitives: EntityPrimitives,
 }

tests/codegen/waiter-tests/src/test/kotlin/com/test/WaiterTest.kt

@@ -681,4 +681,68 @@ class WaiterTest {
             }
         },
     )
+
+    // subfield projection
+    @Test fun testHasStructWithStringByProjection() = successTest(
+        WaitersTestClient::waitUntilHasStructWithStringByProjection,
+        GetEntityResponse { },
+        GetEntityResponse { lists = EntityLists { } },
+        GetEntityResponse {
+            lists = EntityLists { structs = listOf() }
+        },
+        GetEntityResponse {
+            lists = EntityLists { structs = listOf(Struct { }) }
+        },
+        GetEntityResponse {
+            lists = EntityLists {
+                structs = listOf(
+                    Struct { primitives = EntityPrimitives { string = "bar" } },
+                )
+            }
+        },
+        GetEntityResponse {
+            lists = EntityLists {
+                structs = listOf(
+                    Struct { primitives = EntityPrimitives { string = "bar" } },
+                    Struct { primitives = EntityPrimitives { string = "foo" } },
+                )
+            }
+        },
+    )
+    @Test fun testHasStructWithSubstructWithStringByProjection() = successTest(
+        WaitersTestClient::waitUntilHasStructWithSubstructWithStringByProjection,
+        GetEntityResponse { },
+        GetEntityResponse { lists = EntityLists { } },
+        GetEntityResponse {
+            lists = EntityLists { structs = listOf() }
+        },
+        GetEntityResponse {
+            lists = EntityLists {
+                structs = listOf(
+                    Struct { subStructs = listOf(SubStruct { }) },
+                )
+            }
+        },
+        GetEntityResponse {
+            lists = EntityLists {
+                structs = listOf(
+                    Struct { subStructs = listOf(SubStruct { subStructPrimitives = EntityPrimitives { string = "bar" } }) },
+                    Struct { subStructs = listOf(SubStruct { }) },
+                )
+            }
+        },
+        GetEntityResponse {
+            lists = EntityLists {
+                structs = listOf(
+                    Struct {
+                        subStructs = listOf(
+                            SubStruct { subStructPrimitives = EntityPrimitives { string = "bar" } },
+                            SubStruct { subStructPrimitives = EntityPrimitives { string = "baz" } },
+                        )
+                    },
+                    Struct { subStructs = listOf(SubStruct { subStructPrimitives = EntityPrimitives { string = "foo" } }) },
+                )
+            }
+        },
+    )
 }