Fix error reporting to match with strada for case sensitive file system

Author: sheetalkamat

internal/compiler/filesparser.go

@@ -233,9 +233,9 @@ func (w *filesParser) getProcessedFiles(loader *fileLoader) processedFiles {
 	filesByPath := make(map[tspath.Path]*ast.SourceFile, totalFileCount)
 	// stores 'filename -> file association' ignoring case
 	// used to track cases when two file names differ only in casing
-	var filesByNameIgnoreCase map[string]*ast.SourceFile
+	var tasksSeenByNameIgnoreCase map[string]*parseTask
 	if loader.comparePathsOptions.UseCaseSensitiveFileNames {
-		filesByNameIgnoreCase = make(map[string]*ast.SourceFile, totalFileCount)
+		tasksSeenByNameIgnoreCase = make(map[string]*parseTask, totalFileCount)
 	}
 
 	loader.includeProcessor.fileIncludeReasons = make(map[tspath.Path][]*FileIncludeReason, totalFileCount)
@@ -284,6 +284,15 @@ func (w *filesParser) getProcessedFiles(loader *fileLoader) processedFiles {
 				seen[data] = task.normalizedFilePath
 			}
 
+			if tasksSeenByNameIgnoreCase != nil {
+				pathLowerCase := tspath.ToFileNameLowerCase(string(task.path))
+				if taskByIgnoreCase, ok := tasksSeenByNameIgnoreCase[pathLowerCase]; ok {
+					loader.includeProcessor.addProcessingDiagnosticsForFileCasing(taskByIgnoreCase.path, taskByIgnoreCase.normalizedFilePath, task.normalizedFilePath, includeReason)
+				} else {
+					tasksSeenByNameIgnoreCase[pathLowerCase] = task
+				}
+			}
+
 			for _, trace := range task.typeResolutionsTrace {
 				loader.opts.Host.Trace(trace.Message, trace.Args...)
 			}
@@ -316,15 +325,6 @@ func (w *filesParser) getProcessedFiles(loader *fileLoader) processedFiles {
 				continue
 			}
 
-			if filesByNameIgnoreCase != nil {
-				pathLowerCase := tspath.ToFileNameLowerCase(string(path))
-				if existingFile, ok := filesByNameIgnoreCase[pathLowerCase]; ok {
-					loader.includeProcessor.addProcessingDiagnosticsForFileCasing(path, existingFile.FileName(), file.FileName(), includeReason)
-				} else {
-					filesByNameIgnoreCase[pathLowerCase] = file
-				}
-			}
-
 			if task.libFile != nil {
 				libFiles = append(libFiles, file)
 				libFilesMap[path] = task.libFile

testdata/baselines/reference/tsc/forceConsistentCasingInFileNames/two-files-exist-on-disk-that-differs-only-in-casing.js

@@ -15,15 +15,20 @@ export const y = 20;
 tsgo 
 ExitStatus:: DiagnosticsPresent_OutputsGenerated
 Output::
-[91merror[0m[90m TS1149: [0mFile name '/home/src/workspaces/project/d.ts' differs from already included file name '/home/src/workspaces/project/D.ts' only in casing.
+[96mc.ts[0m:[93m1[0m:[93m17[0m - [91merror[0m[90m TS1261: [0mAlready included file name '/home/src/workspaces/project/D.ts' differs from file name '/home/src/workspaces/project/d.ts' only in casing.
   The file is in the program because:
+    Imported via "./D" from file '/home/src/workspaces/project/c.ts'
     Part of 'files' list in tsconfig.json
+
+1 import {x} from "./D"
+                  ~~~~~
+
   tsconfig.json:2:23 - File is matched by 'files' list specified here.
     2     "files": ["c.ts", "d.ts"]
                             ~~~~~~
 
 
-Found 1 error.
+Found 1 error in c.ts[90m:1[0m
 
 //// [/home/src/tslibs/TS/Lib/lib.d.ts] *Lib*
 /// <reference no-default-lib="true"/>