Merge pull request #10 from matthewshirley/feat/errors

Improve Shell Output When An Error Occurs

Author: matthewshirley

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
         env:
           PACT_DART_LIB_DOWNLOAD_PATH: .
       - name: Format coverage
-        run: dart run coverage:format_coverage --lcov --in=coverage --out=coverage.lcov --packages=.packages --report-on=lib
+        run: dart run coverage:format_coverage --lcov --in=coverage --out=coverage.lcov --report-on=lib
       - uses: codecov/codecov-action@v2
         with:
           files: ./coverage.lcov

lib/src/bindings/bindings.dart

@@ -49,6 +49,13 @@ class PactFFIBindings {
 
   late int Function(int mock_server_port) pactffi_mock_server_matched;
 
+  /// External interface to get all the mismatches from a mock server. The port number of the
+  /// mock server is passed in, and a pointer to a C string with the mismatches in JSON
+  /// format is returned.
+  ///
+  /// https://docs.rs/pact_ffi/0.3.3/pact_ffi/mock_server/fn.pactffi_mock_server_mismatches.html
+  /// https://docs.rs/pact_ffi/0.3.3/src/pact_ffi/mock_server/mod.rs.html#391-414
+  ///
   late Pointer<Utf8> Function(int mock_server_port)
       pactffi_mock_server_mismatches;
 
@@ -60,6 +67,13 @@ class PactFFIBindings {
 
   late int Function(int mock_server_port) pactffi_cleanup_mock_server;
 
+  /// Get a description of a mismatch.
+  ///
+  /// https://docs.rs/pact_ffi/0.3.3/pact_ffi/fn.pactffi_mismatch_description.html
+  /// https://docs.rs/pact_ffi/0.3.3/src/pact_ffi/lib.rs.html#265-274
+  late Pointer<Utf8> Function(Pointer<Utf8> mismatches)
+      pactffi_mismatch_description;
+
   PactFFIBindings() {
     pactffi = openLibrary();
 
@@ -147,6 +161,11 @@ class PactFFIBindings {
         .lookup<NativeFunction<pactffi_cleanup_mock_server_native>>(
             'pactffi_cleanup_mock_server')
         .asFunction();
+
+    pactffi_mismatch_description = pactffi
+        .lookup<NativeFunction<pactffi_mismatch_description_native>>(
+            'pactffi_mismatch_description')
+        .asFunction();
   }
 }
 

lib/src/bindings/signatures.dart

@@ -74,6 +74,12 @@ typedef pactffi_mock_server_logs_native = Pointer<Utf8> Function(
 typedef pactffi_mock_server_matched_native = Int8 Function(
     Int32 mock_server_port);
 
+/// External interface to get all the mismatches from a mock server. The port number of the
+/// mock server is passed in, and a pointer to a C string with the mismatches in JSON
+/// format is returned.
+///
+/// https://docs.rs/pact_ffi/0.3.3/pact_ffi/mock_server/fn.pactffi_mock_server_mismatches.html
+/// https://docs.rs/pact_ffi/0.3.3/src/pact_ffi/mock_server/mod.rs.html#391-414
 typedef pactffi_mock_server_mismatches_native = Pointer<Utf8> Function(
     Int32 mock_server_port);
 
@@ -147,3 +153,10 @@ typedef pactffi_write_message_pact_file_native = Int32 Function(
 
 typedef pactffi_write_pact_file_native = Int32 Function(
     Int32 mock_server_port, Pointer<Utf8> directory, Int8 overwrite);
+
+/// Get a description of a mismatch.
+///
+/// https://docs.rs/pact_ffi/0.3.3/pact_ffi/fn.pactffi_mismatch_description.html
+/// https://docs.rs/pact_ffi/0.3.3/src/pact_ffi/lib.rs.html#265-274
+typedef pactffi_mismatch_description_native = Pointer<Utf8> Function(
+    Pointer<Utf8> mismatch);

lib/src/errors.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 class EmptyParameterError extends Error {
   String parameter = '';
 
@@ -31,14 +33,103 @@ class PactMatcherError extends Error {
   String toString() => 'Unable to create PactMatcher. $reason';
 }
 
-class PactMismatchError extends Error {
-  final String mismatches;
+enum MismatchErrorType {
+  MissingRequest,
+  RequestNotFound,
+  RequestMismatch,
+  MockServerParsingFail,
+  Unknown;
+
+  static MismatchErrorType fromType(String type) {
+    switch (type) {
+      case 'missing-request':
+        return MissingRequest;
+
+      case 'request-not-found':
+        return RequestNotFound;
+
+      case 'request-mismatch':
+        return RequestMismatch;
+
+      case 'mock-server-parsing-fail':
+        return MockServerParsingFail;
+
+      default:
+        return Unknown;
+    }
+  }
+}
+
+extension MismatchErrorTypeReason on MismatchErrorType {
+  static var errorReasons = {
+    MismatchErrorType.MissingRequest: 'Request was missing',
+    MismatchErrorType.RequestNotFound: 'Request was unexpected',
+    MismatchErrorType.RequestMismatch: 'Request was not matched',
+    MismatchErrorType.MockServerParsingFail:
+        'Mock Server was uanble to parse the failure.',
+    MismatchErrorType.Unknown: 'Something went wrong.'
+  };
+
+  String get reason => errorReasons[this] ?? 'Something went wrong';
+}
+
+class PactMatchFailure extends Error {
+  late List errors;
 
-  PactMismatchError(this.mismatches);
+  PactMatchFailure(String mismatches) {
+    errors = jsonDecode(mismatches);
+  }
 
   @override
-  String toString() =>
-      'Pact was unable to verify all interactions. Pact returned: $mismatches';
+  String toString() {
+    var output = 'Pact was unable to validate one or more interaction(s):\n\n';
+    var errorReason = '';
+
+    var index = 1;
+    errors.forEach((error) {
+      var errorType = MismatchErrorType.fromType(error['type']);
+      errorReason = errorType.reason;
+      var expected = '';
+      var actual = '';
+
+      switch (errorType) {
+        case MismatchErrorType.MissingRequest:
+          expected += '${error['method']} ${error['path']}';
+          break;
+
+        case MismatchErrorType.RequestNotFound:
+          expected += '';
+          actual += '${error['method']} ${error['path']}';
+          break;
+
+        case MismatchErrorType.RequestMismatch:
+          var mismatches = error['mismatches'];
+          errorReason += " (${error['method']} ${error['path']})";
+
+          mismatches.forEach((mismatch) {
+            expected += '- ${mismatch['mismatch']}\n\t\t';
+          });
+          break;
+
+        default:
+          break;
+      }
+
+      output += 'Interaction Mismatch #$index\n';
+      output += '\tReason:\n\t\t$errorReason\n';
+      if (expected.isNotEmpty) {
+        output += '\n\tExpected:\n\t\t$expected\n';
+      }
+
+      if (actual.isNotEmpty) {
+        output += '\n\tActual:\n\t\t$actual\n\n';
+      }
+
+      index++;
+    });
+
+    return output;
+  }
 }
 
 class PactCreateMockServerError extends Error {

lib/src/interaction.dart

@@ -1,9 +1,11 @@
 import 'dart:convert';
+import 'dart:ffi';
 import 'package:ffi/ffi.dart';
 
 import 'package:pact_dart/src/bindings/types.dart';
 import 'package:pact_dart/src/bindings/bindings.dart';
 import 'package:pact_dart/src/errors.dart';
+import 'package:pact_dart/src/utils/content_type.dart';
 
 class Interaction {
   late InteractionHandle interaction;
@@ -62,17 +64,25 @@ class Interaction {
     });
   }
 
-  void _withBody(InteractionPart part, String contentType, Map body) {
-    final cContentType = contentType.toNativeUtf8();
+  void _withBody<T>(InteractionPart part, T body, String? contentType) {
+    Pointer<Utf8> cContentType;
+
+    if (contentType != null) {
+      cContentType = contentType.toNativeUtf8();
+    } else {
+      cContentType = getContentType(body).toNativeUtf8();
+    }
+
     final cBody = jsonEncode(body).toNativeUtf8();
 
     bindings.pactffi_with_body(interaction, part.value, cContentType, cBody);
   }
 
-  Interaction withRequest(String method, String path,
+  Interaction withRequest<T>(String method, String path,
       {Map<String, String>? headers,
       Map<String, String>? query,
-      dynamic body}) {
+      T? body,
+      String? contentType}) {
     if (method.isEmpty || path.isEmpty) {
       throw EmptyParametersError(['method', 'path']);
     }
@@ -95,24 +105,26 @@ class Interaction {
     }
 
     if (body != null) {
-      _withBody(InteractionPart.Request, 'application/json',
-          body); // TODO: Assumes all requests are JSON
+      _withBody(InteractionPart.Request, body, contentType);
     }
 
     return this;
   }
 
-  Interaction willRespondWith(int status,
-      {Map<String, String>? headers, Map? body}) {
+  Interaction willRespondWith<T>(
+    int status, {
+    Map<String, String>? headers,
+    T? body,
+    String? contentType,
+  }) {
     bindings.pactffi_response_status(interaction, status);
 
     if (headers != null) {
       _withHeaders(InteractionPart.Response, headers);
     }
 
     if (body != null) {
-      _withBody(InteractionPart.Response, 'application/json',
-          body); // TODO: Assumes all requests are JSON
+      _withBody(InteractionPart.Response, body, contentType);
     }
 
     return this;

lib/src/pact_mock_service.dart

@@ -76,15 +76,16 @@ class PactMockService {
     }
   }
 
+  void onPactMismatches() {}
+
   /// Verifies the interactions were matched and writes the JSON contract
   void writePactFile({String directory = 'contracts', bool overwrite = false}) {
     final hasMatchedInteractions = this.hasMatchedInteractions();
 
     if (!hasMatchedInteractions) {
       final mismatches =
           bindings.pactffi_mock_server_mismatches(port).toDartString();
-
-      throw PactMismatchError(mismatches);
+      throw PactMatchFailure(mismatches);
     }
 
     final result = bindings.pactffi_write_pact_file(

lib/src/utils/content_type.dart

@@ -0,0 +1,7 @@
+String getContentType(content) {
+  if (content is Map) {
+    return 'application/json';
+  }
+
+  return 'text/plain';
+}

pubspec.lock

@@ -352,4 +352,4 @@ packages:
     source: hosted
     version: "3.1.0"
 sdks:
-  dart: ">=2.12.0 <3.0.0"
+  dart: ">=2.17.0 <3.0.0"

pubspec.yaml

@@ -4,7 +4,7 @@ version: 0.5.0
 homepage: https://github.com/matthewshirley/pact_dart
 
 environment:
-  sdk: ">=2.12.0 <3.0.0"
+  sdk: ">=2.17.0 <3.0.0"
 
 dependencies:
   ffi: ^1.1.2