[Test] Fix testParallelDependencyScanningDiagnostics to handle new diagnostics with source-locations

Author: artemcm

Tests/SwiftDriverTests/ExplicitModuleBuildTests.swift

@@ -1817,8 +1817,33 @@ final class ExplicitModuleBuildTests: XCTestCase {
         for scanIndex in 0..<numFiles {
           let diagnostics = scanDiagnostics[scanIndex]
           XCTAssertEqual(diagnostics.count, 2)
-          XCTAssertEqual(diagnostics[0].message, "Unable to find module dependency: 'UnknownModule\(scanIndex)'")
-          XCTAssertEqual(diagnostics[1].message, "a dependency of main module 'testParallelDependencyScanningDiagnostics\(scanIndex)'")
+          // Diagnostic source locations came after per-scan diagnostics, only meaningful
+          // on this test code-path
+          if try dependencyOracle.supportsDiagnosticSourceLocations() {
+              let sourceLoc = try XCTUnwrap(diagnostics[0].sourceLocation)
+              XCTAssertEqual(sourceLoc.lineNumber, 1)
+              XCTAssertEqual(sourceLoc.columnNumber, 8)
+              XCTAssertEqual(diagnostics[0].message,
+              """
+              Unable to find module dependency: 'UnknownModule\(scanIndex)'
+              import UnknownModule\(scanIndex);
+                     ^
+
+              """)
+              let noteSourceLoc = try XCTUnwrap(diagnostics[1].sourceLocation)
+              XCTAssertEqual(noteSourceLoc.lineNumber, 1)
+              XCTAssertEqual(noteSourceLoc.columnNumber, 8)
+              XCTAssertEqual(diagnostics[1].message,
+              """
+              a dependency of main module 'testParallelDependencyScanningDiagnostics\(scanIndex)'
+              import UnknownModule\(scanIndex);
+                     ^
+
+              """)
+          } else {
+              XCTAssertEqual(diagnostics[0].message, "Unable to find module dependency: 'UnknownModule\(scanIndex)'")
+              XCTAssertEqual(diagnostics[1].message, "a dependency of main module 'testParallelDependencyScanningDiagnostics\(scanIndex)'")
+          }
         }
       } else {
         let globalDiagnostics = try dependencyOracle.getScannerDiagnostics()
@@ -2116,7 +2141,7 @@ final class ExplicitModuleBuildTests: XCTestCase {
   }
 
   func testTraceDependency() throws {
-    try withTemporaryDirectory { path in
+      try withTemporaryDirectory { path in
       try localFileSystem.changeCurrentWorkingDirectory(to: path)
       let moduleCachePath = path.appending(component: "ModuleCache")
       try localFileSystem.createDirectory(moduleCachePath)