[6.1] Suppress warning about #require(nonOptional) in some cases. (#949)

- **Explanation**: Suppress some warnings that occur due to swiftlang/swift#79202 when the compiler selects the wrong overload of `try #require()` for expansion. - **Scope**: Tests using `try #require()` with reference types. - **Issues**: works around swiftlang/swift#79202 - **Original PRs**: #947 - **Risk**: Low, just suppresses some warnings we generate (lack of these warnings is not harmful) - **Testing**: Added a unit test - **Reviewers**: @briancroom

Author: grynspan

Sources/TestingMacros/ConditionMacro.swift

@@ -324,7 +324,24 @@ public struct NonOptionalRequireMacro: RefinedConditionMacro {
  in context: some MacroExpansionContext
  ) throws -> ExprSyntax {
  if let argument = macro.arguments.first {
+#if !SWT_FIXED_137943258
+ // Silence this warning if we see a token (`?`, `nil`, or "Optional") that
+ // might indicate the test author expects the expression is optional.
+ let tokenKindsIndicatingOptionality: [TokenKind] = [
+ .infixQuestionMark,
+ .postfixQuestionMark,
+ .keyword(.nil),
+ .identifier("Optional")
+ ]
+ let looksOptional = argument.tokens(viewMode: .sourceAccurate).lazy
+ .map(\.tokenKind)
+ .contains(where: tokenKindsIndicatingOptionality.contains)
+ if !looksOptional {
+ context.diagnose(.nonOptionalRequireIsRedundant(argument.expression, in: macro))
+ }
+#else
  context.diagnose(.nonOptionalRequireIsRedundant(argument.expression, in: macro))
+#endif
  }
 
  // Perform the normal macro expansion for #require().

Tests/TestingMacrosTests/ConditionMacroTests.swift

@@ -352,6 +352,22 @@ struct ConditionMacroTests {
  #expect(diagnostic.message.contains("is redundant"))
  }
 
+#if !SWT_FIXED_137943258
+ @Test(
+ "#require(optional value mistyped as non-optional) diagnostic is suppressed",
+ .bug("https://github.com/swiftlang/swift/issues/79202"),
+ arguments: [
+ "#requireNonOptional(expression as? T)",
+ "#requireNonOptional(expression as Optional<T>)",
+ "#requireNonOptional(expression ?? nil)",
+ ]
+ )
+ func requireNonOptionalDiagnosticSuppressed(input: String) throws {
+ let (_, diagnostics) = try parse(input)
+ #expect(diagnostics.isEmpty)
+ }
+#endif
+
  @Test("#require(throws: Never.self) produces a diagnostic",
  arguments: [
  "#requireThrows(throws: Swift.Never.self)",