ExplainFiles to handle duplicated files

[sheetalkamat]

No description provided.

[Copilot]

Pull request overview

This pull request implements support for explaining redirect/deduplicated files in the --explainFiles compiler output. When the same package (same name@version) is installed in multiple node_modules locations due to symlinks or other reasons, TypeScript deduplicates them by redirecting to a canonical instance. This PR ensures these redirect files are properly explained in the output.

Changes:

• Added redirectsFile type to track redirect files with their insertion position for proper ordering
• Modified ExplainFiles to interleave redirect files with source files in the correct order based on their indices
• Updated explainRedirectAndImpliedFormat to handle both source files and redirect files, generating appropriate diagnostic messages
• Removed unused fileIncludeKind constants and replaced deduplicatedPaths tracking with more precise redirectFilesByPath map

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/compiler/program.go	Updated UpdateProgram to check redirect files early, modified ExplainFiles to interleave redirect and source files, updated HasSameFileNames to compare redirect files
internal/compiler/processingDiagnostic.go	Changed explainRedirectAndImpliedFormat signature to accept filePath instead of *ast.SourceFile
internal/compiler/includeprocessor.go	Enhanced explainRedirectAndImpliedFormat to handle redirect files and generate redirect diagnostic messages
internal/compiler/filesparser.go	Added logic to create redirectsFile entries when duplicates are detected, adjusted indices for proper ordering
internal/compiler/fileloader.go	Added redirectsFile type and replaced deduplicatedPaths with redirectFilesByPath in processedFiles
internal/compiler/fileInclude.go	Removed unused fileIncludeKindSourceFromProjectReference and fileIncludeKindOutputFromProjectReference constants and related code
internal/execute/tsctests/tsc_test.go	Removed TODO comments for now-implemented features
testdata/baselines/reference/tsc/declarationEmit/*.js	Updated test baselines to include redirect file explanations