Pass tsconfig to esbuild for support of "paths" aliases

.changeset/soft-pets-yawn.md

@@ -0,0 +1,8 @@
+---
+"@workflow/sveltekit": patch
+"@workflow/builders": patch
+"@workflow/astro": patch
+"@workflow/next": patch
+---
+
+Pass `tsconfig` to esbuild for support of "paths" aliases

lib/steps/paths-alias-test.ts

@@ -0,0 +1,9 @@
+/**
+ * This is a utility function from outside the workbench app directory.
+ * It is used to test that esbuild can resolve tsconfig path aliases.
+ * Note: This is NOT a step function - it's a regular function that gets called
+ * from within a step to verify path alias imports work correctly.
+ */
+export function pathsAliasHelper(): string {
+  return 'pathsAliasHelper';
+}

packages/astro/src/builder.ts

@@ -50,13 +50,12 @@ export class LocalBuilder extends BaseBuilder {
 
     // Get workflow and step files to bundle
     const inputFiles = await this.getInputFiles();
-    const tsConfig = await this.getTsConfigOptions();
+    const tsconfigPath = await this.findTsConfigPath();
 
     const options = {
       inputFiles,
       workflowGeneratedDir,
-      tsBaseUrl: tsConfig.baseUrl,
-      tsPaths: tsConfig.paths,
+      tsconfigPath,
     };
 
     // Generate the three Astro route handlers
@@ -68,13 +67,11 @@ export class LocalBuilder extends BaseBuilder {
   private async buildStepsRoute({
     inputFiles,
     workflowGeneratedDir,
-    tsPaths,
-    tsBaseUrl,
+    tsconfigPath,
   }: {
     inputFiles: string[];
     workflowGeneratedDir: string;
-    tsBaseUrl?: string;
-    tsPaths?: Record<string, string[]>;
+    tsconfigPath?: string;
   }) {
     // Create steps route: .well-known/workflow/v1/step.js
     const stepsRouteFile = join(workflowGeneratedDir, 'step.js');
@@ -83,8 +80,7 @@ export class LocalBuilder extends BaseBuilder {
       inputFiles,
       outfile: stepsRouteFile,
       externalizeNonSteps: true,
-      tsBaseUrl,
-      tsPaths,
+      tsconfigPath,
     });
 
     let stepsRouteContent = await readFile(stepsRouteFile, 'utf-8');
@@ -106,13 +102,11 @@ export const prerender = false;`
   private async buildWorkflowsRoute({
     inputFiles,
     workflowGeneratedDir,
-    tsPaths,
-    tsBaseUrl,
+    tsconfigPath,
   }: {
     inputFiles: string[];
     workflowGeneratedDir: string;
-    tsBaseUrl?: string;
-    tsPaths?: Record<string, string[]>;
+    tsconfigPath?: string;
   }) {
     // Create workflows route: .well-known/workflow/v1/flow.js
     const workflowsRouteFile = join(workflowGeneratedDir, 'flow.js');
@@ -121,8 +115,7 @@ export const prerender = false;`
       outfile: workflowsRouteFile,
       bundleFinalOutput: false,
       inputFiles,
-      tsBaseUrl,
-      tsPaths,
+      tsconfigPath,
     });
 
     let workflowsRouteContent = await readFile(workflowsRouteFile, 'utf-8');

packages/builders/package.json

@@ -45,7 +45,6 @@
     "@workflow/core": "workspace:*",
     "builtin-modules": "5.0.0",
     "chalk": "5.6.2",
-    "comment-json": "4.2.5",
     "enhanced-resolve": "5.18.2",
     "esbuild": "catalog:",
     "find-up": "7.0.0",

packages/builders/src/apply-swc-transform.ts

@@ -23,12 +23,7 @@ export type WorkflowManifest = {
 export async function applySwcTransform(
   filename: string,
   source: string,
-  mode: 'workflow' | 'step' | 'client' | false,
-  jscConfig?: {
-    paths?: Record<string, string[]>;
-    // this must be absolute path
-    baseUrl?: string;
-  }
+  mode: 'workflow' | 'step' | 'client' | false
 ): Promise<{
   code: string;
   workflowManifest: WorkflowManifest;
@@ -62,9 +57,6 @@ export async function applySwcTransform(
             plugins: [[require.resolve('@workflow/swc-plugin'), { mode }]],
           }
         : undefined,
-
-      ...jscConfig,
-
       transform: {
         react: {
           runtime: 'preserve',

packages/builders/src/base-builder.ts

@@ -3,7 +3,6 @@ import { mkdir, readFile, rename, writeFile } from 'node:fs/promises';
 import { basename, dirname, join, relative, resolve } from 'node:path';
 import { promisify } from 'node:util';
 import chalk from 'chalk';
-import { parse } from 'comment-json';
 import enhancedResolveOriginal from 'enhanced-resolve';
 import * as esbuild from 'esbuild';
 import { findUp } from 'find-up';
@@ -40,52 +39,12 @@ export abstract class BaseBuilder {
   abstract build(): Promise<void>;
 
   /**
-   * Extracts TypeScript path mappings and baseUrl from tsconfig.json/jsconfig.json.
-   * Used to properly resolve module imports during bundling.
+   * Finds tsconfig.json/jsconfig.json for the project.
+   * Used by esbuild to properly resolve module imports during bundling.
    */
-  protected async getTsConfigOptions(): Promise<{
-    baseUrl?: string;
-    paths?: Record<string, string[]>;
-  }> {
-    const options: {
-      paths?: Record<string, string[]>;
-      baseUrl?: string;
-    } = {};
-
+  protected async findTsConfigPath(): Promise<string | undefined> {
     const cwd = this.config.workingDir || process.cwd();
-
-    const tsJsConfig = await findUp(['tsconfig.json', 'jsconfig.json'], {
-      cwd,
-    });
-
-    if (tsJsConfig) {
-      try {
-        const rawJson = await readFile(tsJsConfig, 'utf8');
-        const parsed: null | {
-          compilerOptions?: {
-            paths?: Record<string, string[]> | undefined;
-            baseUrl?: string;
-          };
-        } = parse(rawJson) as any;
-
-        if (parsed) {
-          options.paths = parsed.compilerOptions?.paths;
-
-          if (parsed.compilerOptions?.baseUrl) {
-            options.baseUrl = resolve(cwd, parsed.compilerOptions.baseUrl);
-          } else {
-            options.baseUrl = cwd;
-          }
-        }
-      } catch (err) {
-        console.error(
-          `Failed to parse ${tsJsConfig} aliases might not apply properly`,
-          err
-        );
-      }
-    }
-
-    return options;
+    return findUp(['tsconfig.json', 'jsconfig.json'], { cwd });
   }
 
   /**
@@ -288,11 +247,9 @@ export abstract class BaseBuilder {
     format = 'cjs',
     outfile,
     externalizeNonSteps,
-    tsBaseUrl,
-    tsPaths,
+    tsconfigPath,
   }: {
-    tsPaths?: Record<string, string[]>;
-    tsBaseUrl?: string;
+    tsconfigPath?: string;
     inputFiles: string[];
     outfile: string;
     format?: 'cjs' | 'esm';
@@ -394,6 +351,8 @@ export abstract class BaseBuilder {
       minify: false,
       jsx: 'preserve',
       logLevel: 'error',
+      // Use tsconfig for path alias resolution
+      tsconfig: tsconfigPath,
       resolveExtensions: [
         '.ts',
         '.tsx',
@@ -411,8 +370,6 @@ export abstract class BaseBuilder {
           mode: 'step',
           entriesToBundle: externalizeNonSteps ? combinedStepFiles : undefined,
           outdir: outfile ? dirname(outfile) : undefined,
-          tsBaseUrl,
-          tsPaths,
           workflowManifest,
         }),
       ],
@@ -447,11 +404,9 @@ export abstract class BaseBuilder {
     format = 'cjs',
     outfile,
     bundleFinalOutput = true,
-    tsBaseUrl,
-    tsPaths,
+    tsconfigPath,
   }: {
-    tsPaths?: Record<string, string[]>;
-    tsBaseUrl?: string;
+    tsconfigPath?: string;
     inputFiles: string[];
     outfile: string;
     format?: 'cjs' | 'esm';
@@ -523,6 +478,8 @@ export abstract class BaseBuilder {
       // This intermediate bundle is executed via runInContext() in a VM, so we need
       // inline source maps to get meaningful stack traces instead of "evalmachine.<anonymous>".
       sourcemap: 'inline',
+      // Use tsconfig for path alias resolution
+      tsconfig: tsconfigPath,
       resolveExtensions: [
         '.ts',
         '.tsx',
@@ -536,8 +493,6 @@ export abstract class BaseBuilder {
       plugins: [
         createSwcPlugin({
           mode: 'workflow',
-          tsBaseUrl,
-          tsPaths,
           workflowManifest,
         }),
         // This plugin must run after the swc plugin to ensure dead code elimination

packages/builders/src/standalone.ts

@@ -11,12 +11,11 @@ export class StandaloneBuilder extends BaseBuilder {
 
   async build(): Promise<void> {
     const inputFiles = await this.getInputFiles();
-    const tsConfig = await this.getTsConfigOptions();
+    const tsconfigPath = await this.findTsConfigPath();
 
     const options = {
       inputFiles,
-      tsBaseUrl: tsConfig.baseUrl,
-      tsPaths: tsConfig.paths,
+      tsconfigPath,
     };
     const manifest = await this.buildStepsBundle(options);
     await this.buildWorkflowsBundle(options);
@@ -38,12 +37,10 @@ export class StandaloneBuilder extends BaseBuilder {
 
   private async buildStepsBundle({
     inputFiles,
-    tsPaths,
-    tsBaseUrl,
+    tsconfigPath,
   }: {
     inputFiles: string[];
-    tsBaseUrl?: string;
-    tsPaths?: Record<string, string[]>;
+    tsconfigPath?: string;
   }) {
     console.log('Creating steps bundle at', this.config.stepsBundlePath);
 
@@ -53,21 +50,18 @@ export class StandaloneBuilder extends BaseBuilder {
     const { manifest } = await this.createStepsBundle({
       outfile: stepsBundlePath,
       inputFiles,
-      tsBaseUrl,
-      tsPaths,
+      tsconfigPath,
     });
 
     return manifest;
   }
 
   private async buildWorkflowsBundle({
     inputFiles,
-    tsPaths,
-    tsBaseUrl,
+    tsconfigPath,
   }: {
     inputFiles: string[];
-    tsBaseUrl?: string;
-    tsPaths?: Record<string, string[]>;
+    tsconfigPath?: string;
   }): Promise<void> {
     console.log(
       'Creating workflows bundle at',
@@ -82,8 +76,7 @@ export class StandaloneBuilder extends BaseBuilder {
     await this.createWorkflowsBundle({
       outfile: workflowBundlePath,
       inputFiles,
-      tsBaseUrl,
-      tsPaths,
+      tsconfigPath,
     });
   }
 

packages/builders/src/swc-esbuild-plugin.ts

@@ -16,8 +16,6 @@ export interface SwcPluginOptions {
   mode: 'step' | 'workflow' | 'client';
   entriesToBundle?: string[];
   outdir?: string;
-  tsPaths?: Record<string, string[]>;
-  tsBaseUrl?: string;
   workflowManifest?: WorkflowManifest;
 }
 
@@ -206,18 +204,7 @@ export function createSwcPlugin(options: SwcPluginOptions): Plugin {
           }
 
           const { code: transformedCode, workflowManifest } =
-            await applySwcTransform(
-              relativeFilepath,
-              source,
-              options.mode,
-              // we need to provide the tsconfig/jsconfig
-              // alias via swc so that we can resolve them
-              // with our custom resolve logic
-              {
-                paths: options.tsPaths,
-                baseUrl: options.tsBaseUrl,
-              }
-            );
+            await applySwcTransform(relativeFilepath, source, options.mode);
 
           if (!options.workflowManifest) {
             options.workflowManifest = {};