Fixed .failed record mode in inline snapshots. (#874)

* Fixed .failed record mode in inline snapshots.

* wip

* wip

* add some test coverage

* wip

Author: mbrandonw

Sources/InlineSnapshotTesting/AssertInlineSnapshot.swift

@@ -100,22 +100,25 @@ import Foundation
           }
         }
         let expected = expected?()
-        guard
-          record != .all,
-          record != .missing || expected != nil
-        else {
+        func recordSnapshot() {
           // NB: Write snapshot state before calling `XCTFail` in case `continueAfterFailure = false`
           inlineSnapshotState[File(path: filePath), default: []].append(
             InlineSnapshot(
               expected: expected,
               actual: actual,
-              wasRecording: record == .all,
+              wasRecording: record == .all || record == .failed,
               syntaxDescriptor: syntaxDescriptor,
               function: "\(function)",
               line: line,
               column: column
             )
           )
+        }
+        guard
+          record != .all,
+          (record != .missing && record != .failed) || expected != nil
+        else {
+          recordSnapshot()
 
           var failure: String
           if syntaxDescriptor.trailingClosureLabel
@@ -162,12 +165,19 @@ import Foundation
         else { return }
 
         let message = message()
-        syntaxDescriptor.fail(
-          """
+        var failureMessage = """
           \(message.isEmpty ? "Snapshot did not match. Difference: …" : message)
-
+          
           \(difference.indenting(by: 2))
-          """,
+          """
+
+        if record == .failed {
+          recordSnapshot()
+          failureMessage += "\n\nA new snapshot was automatically recorded."
+        }
+
+        syntaxDescriptor.fail(
+          failureMessage,
           fileID: fileID,
           file: filePath,
           line: line,
@@ -352,27 +362,27 @@ public struct InlineSnapshotSyntaxDescriptor: Hashable {
     }
   }
 
-  private struct File: Hashable {
-    let path: StaticString
-    static func == (lhs: Self, rhs: Self) -> Bool {
+@_spi(Internals) public struct File: Hashable {
+  public let path: StaticString
+  public static func == (lhs: Self, rhs: Self) -> Bool {
       "\(lhs.path)" == "\(rhs.path)"
     }
-    func hash(into hasher: inout Hasher) {
+  public func hash(into hasher: inout Hasher) {
       hasher.combine("\(self.path)")
     }
   }
 
-  private struct InlineSnapshot: Hashable {
-    var expected: String?
-    var actual: String?
-    var wasRecording: Bool
-    var syntaxDescriptor: InlineSnapshotSyntaxDescriptor
-    var function: String
-    var line: UInt
-    var column: UInt
+@_spi(Internals) public struct InlineSnapshot: Hashable {
+  public var expected: String?
+  public var actual: String?
+  public var wasRecording: Bool
+  public var syntaxDescriptor: InlineSnapshotSyntaxDescriptor
+  public var function: String
+  public var line: UInt
+  public var column: UInt
   }
 
-  private var inlineSnapshotState: [File: [InlineSnapshot]] = [:]
+  @_spi(Internals) public var inlineSnapshotState: [File: [InlineSnapshot]] = [:]
 
   private struct TestSource {
     let source: String

Tests/InlineSnapshotTestingTests/InlineSnapshotTestingTests.swift

@@ -1,5 +1,5 @@
 import Foundation
-import InlineSnapshotTesting
+@_spi(Internals) import InlineSnapshotTesting
 import SnapshotTesting
 import XCTest
 
@@ -286,6 +286,70 @@ final class InlineSnapshotTestingTests: XCTestCase {
       """##
     }
   }
+
+#if canImport(Darwin)
+  func testRecordFailed_IncorrectExpectation() throws {
+    let initialInlineSnapshotState = inlineSnapshotState
+    defer { inlineSnapshotState = initialInlineSnapshotState }
+
+    XCTExpectFailure {
+      withSnapshotTesting(record: .failed) {
+        assertInlineSnapshot(of: 42, as: .json) {
+        """
+        4
+        """
+        }
+      }
+    } issueMatcher: {
+      $0.compactDescription == """
+        failed - Snapshot did not match. Difference: …
+        
+          @@ −1,1 +1,1 @@
+          −4
+          +42
+        
+        A new snapshot was automatically recorded.
+        """
+    }
+
+    XCTAssertEqual(inlineSnapshotState.count, 1)
+    XCTAssertEqual(
+      String(describing: inlineSnapshotState.keys.first!.path)
+        .hasSuffix("InlineSnapshotTestingTests.swift"),
+      true
+    )
+  }
+  #endif
+
+#if canImport(Darwin)
+  func testRecordFailed_MissingExpectation() throws {
+    let initialInlineSnapshotState = inlineSnapshotState
+    defer { inlineSnapshotState = initialInlineSnapshotState }
+
+    XCTExpectFailure {
+      withSnapshotTesting(record: .failed) {
+        assertInlineSnapshot(of: 42, as: .json)
+      }
+    } issueMatcher: {
+      $0.compactDescription == """
+        failed - Automatically recorded a new snapshot. Difference: …
+
+          @@ −1,1 +1,1 @@
+          −
+          +42
+
+        Re-run "testRecordFailed_MissingExpectation()" to assert against the newly-recorded snapshot.
+        """
+    }
+
+    XCTAssertEqual(inlineSnapshotState.count, 1)
+    XCTAssertEqual(
+      String(describing: inlineSnapshotState.keys.first!.path)
+        .hasSuffix("InlineSnapshotTestingTests.swift"),
+      true
+    )
+  }
+  #endif
 }
 
 private func assertCustomInlineSnapshot(