fix(tsbuild): Improve diagnostic error handling and summary reporting for TypeScript compilation by refactoring diagnostic processing and adding pre-emit error checks.

ts/tsbuild.classes.tsbuild.ts

@@ -3,6 +3,16 @@ import * as plugins from './plugins.js';
 import * as paths from './paths.js';
 import type { CompilerOptions, ScriptTarget, ModuleKind } from './tsbuild.exports.js';
 
+/**
+ * Interface for error summary data
+ */
+export interface IErrorSummary {
+  errorsByFile: Record<string, plugins.typescript.Diagnostic[]>;
+  generalErrors: plugins.typescript.Diagnostic[];
+  totalErrors: number;
+  totalFiles: number;
+}
+
 /**
  * Default compiler options for TypeScript compilation
  */
@@ -166,14 +176,9 @@ export class TsBuild {
   }
 
   /**
-   * Helper function to handle and log TypeScript diagnostics
+   * Helper function to process TypeScript diagnostics and return error summary
    */
-  private handleDiagnostics(diagnostics: readonly plugins.typescript.Diagnostic[]): boolean {
-    if (diagnostics.length === 0) {
-      return false;
-    }
-    
-    // Group errors by file for better readability
+  private processDiagnostics(diagnostics: readonly plugins.typescript.Diagnostic[]): IErrorSummary {
     const errorsByFile: Record<string, plugins.typescript.Diagnostic[]> = {};
     const generalErrors: plugins.typescript.Diagnostic[] = [];
     
@@ -190,12 +195,27 @@ export class TsBuild {
       }
     });
     
-    // Print error summary header
-    const totalErrorCount = diagnostics.length;
-    const fileCount = Object.keys(errorsByFile).length;
+    return {
+      errorsByFile,
+      generalErrors,
+      totalErrors: diagnostics.length,
+      totalFiles: Object.keys(errorsByFile).length
+    };
+  }
+
+  /**
+   * Helper function to display error summary
+   */
+  private displayErrorSummary(errorSummary: IErrorSummary): void {
+    if (errorSummary.totalErrors === 0) {
+      return;
+    }
     
+    const { errorsByFile, generalErrors, totalErrors, totalFiles } = errorSummary;
+    
+    // Print error summary header
     console.log('\n' + '='.repeat(80));
-    console.log(`❌ Found ${totalErrorCount} error${totalErrorCount !== 1 ? 's' : ''} in ${fileCount} file${fileCount !== 1 ? 's' : ''}:`);
+    console.log(`❌ Found ${totalErrors} error${totalErrors !== 1 ? 's' : ''} in ${totalFiles} file${totalFiles !== 1 ? 's' : ''}:`);
     console.log('='.repeat(80));
     
     // Color codes for error formatting
@@ -255,8 +275,15 @@ export class TsBuild {
     }
     
     console.log('\n' + '='.repeat(80) + '\n');
-    
-    return diagnostics.length > 0;
+  }
+
+  /**
+   * Helper function to handle and log TypeScript diagnostics (legacy method)
+   */
+  private handleDiagnostics(diagnostics: readonly plugins.typescript.Diagnostic[]): boolean {
+    const errorSummary = this.processDiagnostics(diagnostics);
+    this.displayErrorSummary(errorSummary);
+    return errorSummary.totalErrors > 0;
   }
 
   /**
@@ -282,6 +309,72 @@ export class TsBuild {
     this.options = { ...this.options, ...options };
   }
 
+  /**
+   * The main compiler function that compiles the files and returns error summary
+   */
+  public async compileWithErrorTracking(): Promise<{ emittedFiles: any[], errorSummary: IErrorSummary }> {
+    if (this.options.skipLibCheck) {
+      console.log('\n⚠️  WARNING ⚠️');
+      console.log('You are skipping libcheck... Is that really wanted?');
+      console.log('Continuing in 5 seconds...\n');
+      await plugins.smartdelay.delayFor(5000);
+    }
+    
+    console.log(`🔨 Compiling ${this.fileNames.length} files...`);
+    const done = plugins.smartpromise.defer<{ emittedFiles: any[], errorSummary: IErrorSummary }>();
+    const program = this.createProgram();
+    
+    // Check for pre-emit diagnostics first
+    const preEmitDiagnostics = plugins.typescript.getPreEmitDiagnostics(program);
+    const preEmitErrorSummary = this.processDiagnostics(preEmitDiagnostics);
+    
+    // Only continue to emit phase if no pre-emit errors
+    if (preEmitErrorSummary.totalErrors > 0) {
+      this.displayErrorSummary(preEmitErrorSummary);
+      console.error('\n❌ TypeScript pre-emit checks failed. Please fix the issues listed above before proceeding.');
+      console.error('   Type errors must be resolved before the compiler can emit output files.\n');
+      // Return error summary instead of exiting to allow final summary display
+      done.resolve({ emittedFiles: [], errorSummary: preEmitErrorSummary });
+      return done.promise;
+    }
+    
+    // If no pre-emit errors, proceed with emit
+    const emitResult = program.emit();
+    const emitErrorSummary = this.processDiagnostics(emitResult.diagnostics);
+    
+    // Combine error summaries
+    const combinedErrorSummary: IErrorSummary = {
+      errorsByFile: { ...preEmitErrorSummary.errorsByFile, ...emitErrorSummary.errorsByFile },
+      generalErrors: [...preEmitErrorSummary.generalErrors, ...emitErrorSummary.generalErrors],
+      totalErrors: preEmitErrorSummary.totalErrors + emitErrorSummary.totalErrors,
+      totalFiles: Object.keys({ ...preEmitErrorSummary.errorsByFile, ...emitErrorSummary.errorsByFile }).length
+    };
+
+    const exitCode = emitResult.emitSkipped ? 1 : 0;
+    if (exitCode === 0) {
+      console.log('\n✅ TypeScript emit succeeded!');
+      
+      // Get count of emitted files by type
+      const jsFiles = emitResult.emittedFiles?.filter(f => f.endsWith('.js')).length || 0;
+      const dtsFiles = emitResult.emittedFiles?.filter(f => f.endsWith('.d.ts')).length || 0;
+      const mapFiles = emitResult.emittedFiles?.filter(f => f.endsWith('.map')).length || 0;
+      
+      // If we have emitted files, show a summary
+      if (emitResult.emittedFiles && emitResult.emittedFiles.length > 0) {
+        console.log(`   Generated ${emitResult.emittedFiles.length} files: ${jsFiles} .js, ${dtsFiles} .d.ts, ${mapFiles} source maps`);
+      }
+      
+      done.resolve({ emittedFiles: emitResult.emittedFiles || [], errorSummary: combinedErrorSummary });
+    } else {
+      this.displayErrorSummary(combinedErrorSummary);
+      console.error('\n❌ TypeScript emit failed. Please investigate the errors listed above!');
+      console.error('   No output files have been generated.\n');
+      process.exit(exitCode);
+    }
+
+    return done.promise;
+  }
+
   /**
    * The main compiler function that compiles the files
    */