Only emit diagnostics for unexpected diagram mismatches (#103)

Author: phausler

Tests/AsyncAlgorithmsTests/Support/ValidationTest.swift

@@ -14,10 +14,10 @@ import AsyncAlgorithms
 import AsyncSequenceValidation
 
 extension XCTestCase {
-  func recordFailure(_ description: String, detail: String? = nil, system: Bool = false, at location: AsyncSequenceValidation.SourceLocation) {
+  func recordFailure(_ description: String, system: Bool = false, at location: AsyncSequenceValidation.SourceLocation) {
 #if canImport(Darwin)
     let context = XCTSourceCodeContext(location: XCTSourceCodeLocation(filePath: location.file.description, lineNumber: Int(location.line)))
-    let issue = XCTIssue(type: system ? .system : .assertionFailure, compactDescription: description, detailedDescription: detail, sourceCodeContext: context, associatedError: nil, attachments: [])
+    let issue = XCTIssue(type: system ? .system : .assertionFailure, compactDescription: description, detailedDescription: nil, sourceCodeContext: context, associatedError: nil, attachments: [])
     record(issue)
 #else
     XCTFail(description, file: location.file, line: location.line)
@@ -26,32 +26,36 @@ extension XCTestCase {
 
   func validate<Test: AsyncSequenceValidationTest, Theme: AsyncSequenceValidationTheme>(theme: Theme, expectedFailures: Set<String>, @AsyncSequenceValidationDiagram _ build: (AsyncSequenceValidationDiagram) -> Test, file: StaticString = #file, line: UInt = #line) {
     var expectations = expectedFailures
+    var result: AsyncSequenceValidationDiagram.ExpectationResult?
+    var failures = [AsyncSequenceValidationDiagram.ExpectationFailure]()
     let baseLoc = AsyncSequenceValidation.SourceLocation(file: file, line: line)
+    var accountedFailures = [AsyncSequenceValidationDiagram.ExpectationFailure]()
     do {
-      let (result, failures) = try AsyncSequenceValidationDiagram.test(theme: theme, build)
-      var detail: String?
-      if failures.count > 0 {
-        detail = """
-        Expected
-        \(result.reconstituteExpected(theme: theme))
-        Actual
-        \(result.reconstituteActual(theme: theme))
-        """
-        print("Expected")
-        print(result.reconstituteExpected(theme: theme))
-        print("Actual")
-        print(result.reconstituteActual(theme: theme))
-      }
+      (result, failures) = try AsyncSequenceValidationDiagram.test(theme: theme, build)
       for failure in failures {
         if expectations.remove(failure.description) == nil {
-          recordFailure(failure.description, detail: detail, at: failure.specification?.location ?? baseLoc)
+          recordFailure(failure.description, at: failure.specification?.location ?? baseLoc)
+        } else {
+          accountedFailures.append(failure)
         }
       }
     } catch {
       if expectations.remove("\(error)") == nil {
         recordFailure("\(error)", system: true, at: (error as? SourceFailure)?.location ?? baseLoc)
       }
     }
+    // If no failures were expected and the result reconstitues to something different
+    // than what was expected, dump that out as a failure for easier diagnostics, this
+    // likely should be done via attachments but that does not display inline code
+    // nicely. Ideally we would want to have this display as a runtime warning but those
+    // do not have source line attribution; for now XCTFail is good enough.
+    if let result = result, expectedFailures.count == 0 {
+      let expected = result.reconstituteExpected(theme: theme)
+      let actual = result.reconstituteActual(theme: theme)
+      if expected != actual {
+        XCTFail("Validation failure:\nExpected:\n\(expected)\nActual:\n\(actual)", file: file, line: line)
+      }
+    }
     // any remaining expectations are failures that were expected but did not happen
     for expectation in expectations {
       XCTFail("Expected failure: \(expectation) did not occur.", file: file, line: line)