[Swagger Linter Migration] ConsistentPatchProperties (origin)

packages/typespec-lintdiff/src/rules/consistent-patch-properties.ts

@@ -2,6 +2,7 @@ import { resolveProviderNamespace } from "@azure-tools/typespec-azure-resource-m
 import {
   createRule,
   getDiscriminator,
+  getProperty,
   isNeverType,
   isNullType,
   paramMessage,
@@ -204,16 +205,23 @@ function getPayloadProperties(program: Program, model: Model): Map<string, Paylo
 
   for (let current: Model | undefined = model; current !== undefined; current = current.baseModel) {
     for (const property of current.properties.values()) {
+      // A derived declaration shadows its base even when its payload type is never.
+      if (getProperty(model, property.name) !== property) {
+        continue;
+      }
       const jsonName = resolveEncodedName(program, property, "application/json");
       if (!properties.has(jsonName) && !isNeverType(property.type)) {
         properties.set(jsonName, { target: property, type: property.type });
       }
     }
+  }
 
+  // Resolve the complete authored shape before filling in discriminator metadata.
+  for (let current: Model | undefined = model; current !== undefined; current = current.baseModel) {
     const discriminator = getDiscriminator(program, current);
     if (
       discriminator !== undefined &&
-      !current.properties.has(discriminator.propertyName) &&
+      getProperty(model, discriminator.propertyName) === undefined &&
       !properties.has(discriminator.propertyName)
     ) {
       properties.set(discriminator.propertyName, { target: current });

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/corpus-evidence.json

@@ -2,16 +2,18 @@
   "schemaVersion": 2,
   "rule": "ConsistentPatchProperties",
   "specsCommit": "f6b53f105b95da05276530a0754a1c71b4f16397",
-  "generatedAt": "2026-09-09T09:24:28.545Z",
-  "completedAt": "2026-09-09T17:28:59.7719922+08:00",
-  "sourceBaseCommit": "29c4a87b0799092be0ede854ffdf23a0a9648795",
+  "generatedAt": "2026-09-11T05:20:19.336Z",
+  "completedAt": "2026-09-11T13:23:02.8497634+08:00",
+  "sourceBaseCommit": "ca14b58cdf4dfc8b1fe835c16bf3bbb30f6bdb93",
   "sourceBranch": "feature/lintdiff-consistent-patch-properties-native",
-  "sourceState": "Uncommitted native-boundary repair, before final formatting",
-  "localLinterFingerprint": "sha256:33b2527404c4fb88cc32a37f2dd7cb1d58b17789308bdce020e23635019bd6f1",
+  "sourceState": "Uncommitted inherited authored-discriminator precedence repair, after source formatting",
+  "localLinterFingerprint": "sha256:00fc4e58bfeaff393f9d36ad3bca3cd43da8cd4b00d7e46c811fb19a43e84130",
+  "diagnosticMultisetUnchangedFrom": "2026-09-11T04:09:06.638Z",
+  "diagnosticMultisetIdentity": "project + source file + line + column + message + severity, including multiplicity",
   "coverageKind": "partial",
   "command": "pnpm --dir packages/typespec-lintdiff specs:typespec --specs-repo C:\\dev\\worktrees\\azure-rest-api-specs-lintdiff-consistent-patch-properties --concurrency 6",
   "fullRun": true,
-  "durationMs": 4678050,
+  "durationMs": 1289034,
   "sourceProjectCount": 468,
   "successfulProjectCount": 462,
   "failedProjectCount": 6,
@@ -58,7 +60,7 @@
   "uncertainty": {
     "informatica": "Selected Swagger schema mismatches are verified; the validator-side omission mechanism is not isolated.",
     "versions": "The remaining 306 diagnostics are not a globally latest-version-projected population.",
-    "scope": "Four fixtures prove intentional native/emitter contract differences despite unchanged corpus counts."
+    "scope": "Four scope fixtures, two inherited-never fixtures, and two inherited-discriminator fixtures prove intentional native/emitter contract differences despite unchanged corpus findings."
   },
   "overlapProjects": [
     "specification/apimanagement/resource-manager/Microsoft.ApiManagement/ApiManagement",

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-patch/expect.json

@@ -0,0 +1 @@
+{ "violation": false }

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-patch/main.tsp

@@ -0,0 +1,41 @@
+import "../../lib/imports.tsp";
+
+using TypeSpec.Http;
+using Azure.ResourceManager;
+
+@armProviderNamespace
+@service(#{ title: "Inherited encoded PATCH discriminator" })
+namespace Microsoft.TestService;
+
+/** Authored payload inherited by the discriminated model. */
+model Base {
+  /** Object represented as kind in the JSON payload. */
+  @encodedName("application/json", "kind")
+  payload?: {
+    /** Property missing from the scalar resource kind. */
+    extra?: string;
+  };
+}
+
+/** Discriminator metadata must not replace the inherited authored object. */
+@discriminator("kind")
+model Details extends Base {}
+
+interface Operations extends Azure.ResourceManager.Operations {}
+
+/** Update the resource. */
+@route("/widgets")
+@patch
+op update(
+  /** Update body. */
+  @body body: {
+    /** Update details. */
+    details?: Details;
+  },
+): {
+  /** Resource details. */
+  details?: {
+    /** Scalar kind. */
+    kind?: string;
+  };
+};

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-patch/output.json

@@ -0,0 +1,160 @@
+{
+  "swagger": "2.0",
+  "info": {
+    "title": "Inherited encoded PATCH discriminator",
+    "version": "0000-00-00",
+    "x-typespec-generated": [
+      {
+        "emitter": "@azure-tools/typespec-autorest"
+      }
+    ]
+  },
+  "schemes": [
+    "https"
+  ],
+  "host": "management.azure.com",
+  "produces": [
+    "application/json"
+  ],
+  "consumes": [
+    "application/json"
+  ],
+  "security": [
+    {
+      "azure_auth": [
+        "user_impersonation"
+      ]
+    }
+  ],
+  "securityDefinitions": {
+    "azure_auth": {
+      "type": "oauth2",
+      "description": "Azure Active Directory OAuth2 Flow.",
+      "flow": "implicit",
+      "authorizationUrl": "https://login.microsoftonline.com/common/oauth2/authorize",
+      "scopes": {
+        "user_impersonation": "impersonate your user account"
+      }
+    }
+  },
+  "tags": [
+    {
+      "name": "Operations"
+    }
+  ],
+  "paths": {
+    "/providers/Microsoft.TestService/operations": {
+      "get": {
+        "operationId": "Operations_List",
+        "tags": [
+          "Operations"
+        ],
+        "description": "List the operations for the provider",
+        "parameters": [
+          {
+            "$ref": "../../../../../common-types/resource-management/v3/types.json#/parameters/ApiVersionParameter"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Azure operation completed successfully.",
+            "schema": {
+              "$ref": "../../../../../common-types/resource-management/v3/types.json#/definitions/OperationListResult"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response.",
+            "schema": {
+              "$ref": "../../../../../common-types/resource-management/v3/types.json#/definitions/ErrorResponse"
+            }
+          }
+        },
+        "x-ms-pageable": {
+          "nextLinkName": "nextLink"
+        }
+      }
+    },
+    "/widgets": {
+      "patch": {
+        "operationId": "Update",
+        "description": "Update the resource.",
+        "parameters": [
+          {
+            "name": "body",
+            "in": "body",
+            "description": "Update body.",
+            "required": true,
+            "schema": {
+              "type": "object",
+              "properties": {
+                "details": {
+                  "$ref": "#/definitions/Details",
+                  "description": "Update details."
+                }
+              }
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "The request has succeeded.",
+            "schema": {
+              "type": "object",
+              "properties": {
+                "details": {
+                  "type": "object",
+                  "description": "Resource details.",
+                  "properties": {
+                    "kind": {
+                      "type": "string",
+                      "description": "Scalar kind."
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "definitions": {
+    "Base": {
+      "type": "object",
+      "description": "Authored payload inherited by the discriminated model.",
+      "properties": {
+        "kind": {
+          "type": "object",
+          "description": "Object represented as kind in the JSON payload.",
+          "properties": {
+            "extra": {
+              "type": "string",
+              "description": "Property missing from the scalar resource kind."
+            }
+          },
+          "x-ms-client-name": "payload"
+        }
+      }
+    },
+    "Details": {
+      "type": "object",
+      "description": "Discriminator metadata must not replace the inherited authored object.",
+      "properties": {
+        "kind": {
+          "type": "string",
+          "description": "Discriminator property for Details."
+        }
+      },
+      "discriminator": "kind",
+      "required": [
+        "kind"
+      ],
+      "allOf": [
+        {
+          "$ref": "#/definitions/Base"
+        }
+      ]
+    }
+  },
+  "parameters": {}
+}

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-patch/tsp-diagnostics.json

@@ -0,0 +1,82 @@
+[
+  {
+    "code": "@azure-tools/typespec-azure-core/require-versioned",
+    "severity": "warning",
+    "message": "Azure services should use the versioning library to define versions for their services. Add the '@versioned' decorator to the service namespace."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-resource-manager/arm-common-types-version",
+    "severity": "warning",
+    "message": "Specify the ARM common-types version using the @armCommonTypesVersion decorator on the service namespace or on each version of the service version enum."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/latest-version-of-common-types-must-be-used",
+    "severity": "warning",
+    "message": "Use the latest ARM common-types version 'v6' instead of 'v3'."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/consistent-patch-properties",
+    "severity": "warning",
+    "message": "The property 'details.kind.extra' in the request body either does not appear in the resource model or is nested at the wrong level."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-core/composition-over-inheritance",
+    "severity": "warning",
+    "message": "Model 'Details' is extending 'Microsoft.TestService.Base' that doesn't define a discriminator. If 'Microsoft.TestService.Base' is meant to be used:\n - For composition consider using spread `...` or `model is` instead.\n - As a polymorphic relation, add the `@discriminator` decorator on the base model."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-core/no-string-discriminator",
+    "severity": "warning",
+    "message": "Use an extensible union instead of a plain string (ex: `union PetKind { cat: \"cat\", dog: \"dog\", string };`)"
+  },
+  {
+    "code": "@azure-tools/typespec-azure-resource-manager/no-empty-model",
+    "severity": "warning",
+    "message": "Properties with type:object must have definition of a reference model."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-resource-manager/arm-resource-operation",
+    "severity": "warning",
+    "message": "All operations must be inside an interface declaration."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-resource-manager/arm-resource-operation",
+    "severity": "warning",
+    "message": "All Resource operations must use an api-version parameter. Please include Azure.ResourceManager.ApiVersionParameter in the operation parameter list using the spread (...ApiVersionParameter) operator, or using one of the common resource parameter models."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/avoid-anonymous-parameter",
+    "severity": "warning",
+    "message": "Operation request body should use a named model instead of an anonymous inline model expression."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/avoid-anonymous-types",
+    "severity": "warning",
+    "message": "Operation response body should use a named model instead of an anonymous inline model expression."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/patch-body-parameters-schema",
+    "severity": "warning",
+    "message": "Properties of a PATCH request body must not be required, property:details.kind."
+  },
+  {
+    "code": "tsp-lintdiff-local-linter/xms-examples-required",
+    "severity": "warning",
+    "message": "Please provide x-ms-examples describing minimum/maximum property set for response/request payloads for operations."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-core/no-unnamed-types",
+    "severity": "warning",
+    "message": "Anonymous model should be defined as a named model declaration."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-core/no-unnamed-types",
+    "severity": "warning",
+    "message": "Anonymous model should be defined as a named model declaration."
+  },
+  {
+    "code": "@azure-tools/typespec-azure-core/no-unnamed-types",
+    "severity": "warning",
+    "message": "Anonymous model should be defined as a named model declaration."
+  }
+]

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-patch/validator-diagnostics.json

@@ -0,0 +1 @@
+[]

packages/typespec-lintdiff/test/fixtures/ConsistentPatchProperties/inherited-encoded-discriminator-response/expect.json

@@ -0,0 +1,4 @@
+{
+  "violation": false,
+  "validatorDiagnostics": [{ "code": "ConsistentPatchProperties", "count": 1 }]
+}