Merge pull request #310 from Ben-G/benji/new-havecount-message

[HaveCountMatcher] Implement Shorter Failure Message

Sources/Nimble/FailureMessage.swift

@@ -9,6 +9,10 @@ public class FailureMessage: NSObject {
     public var to: String = "to"
     public var postfixMessage: String = "match"
     public var postfixActual: String = ""
+    /// An optional message that will be appended as a new line and provides additional details
+    /// about the failure. This message will only be visible in the issue navigator / in logs but
+    /// not directly in the source editor since only a single line is presented there.
+    public var extendedMessage: String? = nil
     public var userDescription: String? = nil
 
     public var stringValue: String {
@@ -46,7 +50,11 @@ public class FailureMessage: NSObject {
             value = "\(expected) \(to) \(postfixMessage), got \(actualValue)\(postfixActual)"
         }
         value = stripNewlines(value)
-
+
+        if let extendedMessage = extendedMessage {
+            value += "\n\(stripNewlines(extendedMessage))"
+        }
+
         if let userDescription = userDescription {
             return "\(userDescription)\n\(value)"
         }

Sources/Nimble/Matchers/HaveCount.swift

@@ -1,13 +1,19 @@
 import Foundation
 
+// The `haveCount` matchers do not print the full string representation of the collection value,
+// instead they only print the type name and the expected count. This makes it easier to understand
+// the reason for failed expectations. See: https://github.com/Quick/Nimble/issues/308.
+// The representation of the collection content is provided in a new line as an `extendedMessage`.
+
 /// A Nimble matcher that succeeds when the actual CollectionType's count equals
 /// the expected value
 public func haveCount<T: CollectionType>(expectedValue: T.Index.Distance) -> NonNilMatcherFunc<T> {
     return NonNilMatcherFunc { actualExpression, failureMessage in
         if let actualValue = try actualExpression.evaluate() {
-            failureMessage.postfixMessage = "have \(stringify(actualValue)) with count \(stringify(expectedValue))"
+            failureMessage.postfixMessage = "have \(prettyCollectionType(actualValue)) with count \(stringify(expectedValue))"
             let result = expectedValue == actualValue.count
             failureMessage.actualValue = "\(actualValue.count)"
+            failureMessage.extendedMessage = "Actual Value: \(stringify(actualValue))"
             return result
         } else {
             return false
@@ -20,9 +26,10 @@ public func haveCount<T: CollectionType>(expectedValue: T.Index.Distance) -> Non
 public func haveCount(expectedValue: Int) -> MatcherFunc<NMBCollection> {
     return MatcherFunc { actualExpression, failureMessage in
         if let actualValue = try actualExpression.evaluate() {
-            failureMessage.postfixMessage = "have \(stringify(actualValue)) with count \(stringify(expectedValue))"
+            failureMessage.postfixMessage = "have \(prettyCollectionType(actualValue)) with count \(stringify(expectedValue))"
             let result = expectedValue == actualValue.count
             failureMessage.actualValue = "\(actualValue.count)"
+            failureMessage.extendedMessage = "Actual Value: \(stringify(actualValue))"
             return result
         } else {
             return false

Sources/Nimble/Utils/Stringers.swift

@@ -169,3 +169,49 @@ public func stringify<T>(value: T?) -> String {
     }
 }
 #endif
+
+// MARK: Collection Type Stringers
+
+/// Attempts to generate a pretty type string for a given value. If the value is of a Objective-C
+/// collection type, or a subclass thereof, (e.g. `NSArray`, `NSDictionary`, etc.). 
+/// This function will return the type name of the root class of the class cluster for better
+/// readability (e.g. `NSArray` instead of `__NSArrayI`).
+///
+/// For values that don't have a type of an Objective-C collection, this function returns the
+/// default type description.
+///
+/// - parameter value: A value that will be used to determine a type name.
+///
+/// - returns: The name of the class cluster root class for Objective-C collection types, or the
+/// the `dynamicType` of the value for values of any other type.
+public func prettyCollectionType<T>(value: T) -> String {
+    #if _runtime(_ObjC)
+    // Check for types that are not in corelibs-foundation separately
+    if value is NSHashTable {
+        return String(NSHashTable.self)
+    }
+    #endif
+
+    switch value {
+    case is NSArray:
+        return String(NSArray.self)
+    case is NSDictionary:
+        return String(NSDictionary.self)
+    case is NSSet:
+        return String(NSSet.self)
+    case is NSIndexSet:
+        return String(NSIndexSet.self)
+    default:
+        return String(value)
+    }
+}
+
+/// Returns the type name for a given collection type. This overload is used by Swift
+/// collection types.
+///
+/// - parameter collection: A Swift `CollectionType` value.
+///
+/// - returns: A string representing the `dynamicType` of the value.
+public func prettyCollectionType<T: CollectionType>(collection: T) -> String {
+    return String(collection.dynamicType)
+}

Tests/Nimble/Matchers/HaveCountTest.swift

@@ -14,11 +14,11 @@ class HaveCountTest: XCTestCase, XCTestCaseProvider {
         expect([1, 2, 3]).to(haveCount(3))
         expect([1, 2, 3]).notTo(haveCount(1))
 
-        failsWithErrorMessage("expected to have [1, 2, 3] with count 1, got 3") {
+        failsWithErrorMessage("expected to have Array<Int> with count 1, got 3\nActual Value: [1, 2, 3]") {
             expect([1, 2, 3]).to(haveCount(1))
         }
 
-        failsWithErrorMessage("expected to not have [1, 2, 3] with count 3, got 3") {
+        failsWithErrorMessage("expected to not have Array<Int> with count 3, got 3\nActual Value: [1, 2, 3]") {
             expect([1, 2, 3]).notTo(haveCount(3))
         }
     }
@@ -28,12 +28,13 @@ class HaveCountTest: XCTestCase, XCTestCaseProvider {
         expect(dictionary).to(haveCount(3))
         expect(dictionary).notTo(haveCount(1))
 
-        failsWithErrorMessage("expected to have \(stringify(dictionary)) with count 1, got 3") {
+        failsWithErrorMessage("expected to have Dictionary<String, Int> with count 1, got 3\nActual Value: \(stringify(dictionary))") {
             expect(dictionary).to(haveCount(1))
         }
 
-        failsWithErrorMessage("expected to not have \(stringify(dictionary)) with count 3, got 3") {
-            expect(dictionary).notTo(haveCount(3))
+        failsWithErrorMessage("expected to not have Dictionary<String, Int> with count 3, got 3" +
+            "\nActual Value: \(stringify(dictionary))") {
+                expect(dictionary).notTo(haveCount(3))
         }
     }
 
@@ -42,12 +43,14 @@ class HaveCountTest: XCTestCase, XCTestCaseProvider {
         expect(set).to(haveCount(3))
         expect(set).notTo(haveCount(1))
 
-        failsWithErrorMessage("expected to have \(stringify(set)) with count 1, got 3") {
-            expect(set).to(haveCount(1))
+        failsWithErrorMessage("expected to have Set<Int> with count 1, got 3" +
+            "\nActual Value: \(stringify(set))") {
+                expect(set).to(haveCount(1))
         }
 
-        failsWithErrorMessage("expected to not have \(stringify(set)) with count 3, got 3") {
-            expect(set).notTo(haveCount(3))
+        failsWithErrorMessage("expected to not have Set<Int> with count 3, got 3" +
+            "\nActual Value: \(stringify(set))") {
+                expect(set).notTo(haveCount(3))
         }
     }
 }

Tests/Nimble/objc/ObjCHaveCount.m

@@ -14,11 +14,11 @@ - (void)testHaveCountForNSArray {
     expect(@[]).to(haveCount(@0));
     expect(@[@1]).notTo(haveCount(@0));
 
-    expectFailureMessage(@"expected to have (1, 2, 3) with count 1, got 3", ^{
+    expectFailureMessage(@"expected to have NSArray with count 1, got 3\nActual Value: (1, 2, 3)", ^{
         expect(@[@1, @2, @3]).to(haveCount(@1));
     });
 
-    expectFailureMessage(@"expected to not have (1, 2, 3) with count 3, got 3", ^{
+    expectFailureMessage(@"expected to not have NSArray with count 3, got 3\nActual Value: (1, 2, 3)", ^{
         expect(@[@1, @2, @3]).notTo(haveCount(@3));
     });
 
@@ -28,11 +28,11 @@ - (void)testHaveCountForNSDictionary {
     expect(@{@"1":@1, @"2":@2, @"3":@3}).to(haveCount(@3));
     expect(@{@"1":@1, @"2":@2, @"3":@3}).notTo(haveCount(@1));
 
-    expectFailureMessage(@"expected to have {1 = 1;2 = 2;3 = 3;} with count 1, got 3", ^{
+    expectFailureMessage(@"expected to have NSDictionary with count 1, got 3\nActual Value: {1 = 1;2 = 2;3 = 3;}", ^{
         expect(@{@"1":@1, @"2":@2, @"3":@3}).to(haveCount(@1));
     });
 
-    expectFailureMessage(@"expected to not have {1 = 1;2 = 2;3 = 3;} with count 3, got 3", ^{
+    expectFailureMessage(@"expected to not have NSDictionary with count 3, got 3\nActual Value: {1 = 1;2 = 2;3 = 3;}", ^{
         expect(@{@"1":@1, @"2":@2, @"3":@3}).notTo(haveCount(@3));
     });
 }
@@ -47,15 +47,15 @@ - (void)testHaveCountForNSHashtable {
     expect(table).notTo(haveCount(@1));
 
     NSString *msg = [NSString stringWithFormat:
-                     @"expected to have %@with count 1, got 3",
+                     @"expected to have NSHashTable with count 1, got 3\nActual Value: %@",
                      [table.description stringByReplacingOccurrencesOfString:@"\n" withString:@""]];
     expectFailureMessage(msg, ^{
         expect(table).to(haveCount(@1));
     });
 
 
     msg = [NSString stringWithFormat:
-           @"expected to not have %@with count 3, got 3",
+           @"expected to not have NSHashTable with count 3, got 3\nActual Value: %@",
            [table.description stringByReplacingOccurrencesOfString:@"\n" withString:@""]];
     expectFailureMessage(msg, ^{
         expect(table).notTo(haveCount(@3));
@@ -68,11 +68,11 @@ - (void)testHaveCountForNSSet {
     expect(set).to(haveCount(@3));
     expect(set).notTo(haveCount(@1));
 
-    expectFailureMessage(@"expected to have {(3,1,2)} with count 1, got 3", ^{
+    expectFailureMessage(@"expected to have NSSet with count 1, got 3\nActual Value: {(3,1,2)}", ^{
         expect(set).to(haveCount(@1));
     });
 
-    expectFailureMessage(@"expected to not have {(3,1,2)} with count 3, got 3", ^{
+    expectFailureMessage(@"expected to not have NSSet with count 3, got 3\nActual Value: {(3,1,2)}", ^{
         expect(set).notTo(haveCount(@3));
     });
 }
@@ -83,11 +83,11 @@ - (void)testHaveCountForNSIndexSet {
     expect(set).to(haveCount(@3));
     expect(set).notTo(haveCount(@1));
 
-    expectFailureMessage(@"expected to have (1, 2, 3) with count 1, got 3", ^{
+    expectFailureMessage(@"expected to have NSIndexSet with count 1, got 3\nActual Value: (1, 2, 3)", ^{
         expect(set).to(haveCount(@1));
     });
 
-    expectFailureMessage(@"expected to not have (1, 2, 3) with count 3, got 3", ^{
+    expectFailureMessage(@"expected to not have NSIndexSet with count 3, got 3\nActual Value: (1, 2, 3)", ^{
         expect(set).notTo(haveCount(@3));
     });
 }