assertStateModifications: swift-custom-dump

- Before: assertStateModifications was difficult to use because the diffs for failed assertions were difficult to read
- After: Incorporate CustomDump into assertStateModifications to make the assertions easy to read

Author: gilgtm

Package.resolved

@@ -36,6 +36,15 @@
         "version" : "1.1.4"
       }
     },
+    {
+      "identity" : "swift-custom-dump",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/pointfreeco/swift-custom-dump",
+      "state" : {
+        "revision" : "82645ec760917961cfa08c9c0c7104a57a0fa4b1",
+        "version" : "1.3.3"
+      }
+    },
     {
       "identity" : "swift-identified-collections",
       "kind" : "remoteSourceControl",

Package.swift

@@ -64,6 +64,7 @@ let package = Package(
         .package(url: "https://github.com/pointfreeco/swift-identified-collections", from: "1.0.0"),
         .package(url: "https://github.com/pointfreeco/swift-macro-testing", from: "0.4.0"),
         .package(url: "https://github.com/pointfreeco/swift-perception", from: "1.1.4"),
+        .package(url: "https://github.com/pointfreeco/swift-custom-dump", from: "1.3.3"),
     ],
     targets: [
         // MARK: Workflow
@@ -80,7 +81,10 @@ let package = Package(
         ),
         .target(
             name: "WorkflowTesting",
-            dependencies: ["Workflow"],
+            dependencies: [
+                "Workflow",
+                .product(name: "CustomDump", package: "swift-custom-dump"),
+            ],
             path: "WorkflowTesting/Sources",
             linkerSettings: [.linkedFramework("XCTest")]
         ),

WorkflowTesting/Sources/RenderTesterResult.swift

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import CustomDump
 import Workflow
 import XCTest
 
@@ -129,13 +130,23 @@ extension RenderTesterResult where WorkflowType.State: Equatable {
     ///   and is expected to mutate it to match the new state.
     @discardableResult
     public func assertStateModifications(
-        file: StaticString = #file,
+        _ modifications: (inout WorkflowType.State) throws -> Void,
+        fileID: StaticString = #fileID,
+        filePath: StaticString = #filePath,
         line: UInt = #line,
-        _ modifications: (inout WorkflowType.State) throws -> Void
+        column: UInt = #column
     ) rethrows -> RenderTesterResult<WorkflowType> {
         var initialState = initialState
         try modifications(&initialState)
-        XCTAssertEqual(state, initialState, "Expected state does not match", file: file, line: line)
+        expectNoDifference(
+            initialState,
+            state,
+            "Expected state does not match",
+            fileID: fileID,
+            filePath: filePath,
+            line: line,
+            column: column
+        )
         return self
     }
 }

WorkflowTesting/Tests/WorkflowRenderTesterFailureTests.swift

@@ -341,7 +341,7 @@ final class WorkflowRenderTesterFailureTests: XCTestCase {
         }
     }
 
-    func test_assertState() {
+    func test_assertStateModifications() {
         let result = TestWorkflow()
             .renderTester(initialState: .idle)
             .render { _ in }