feat: resolve tsconfig paths

README.md

@@ -177,3 +177,13 @@ module.exports = {
 }
 ```
 
+### Resolve tsconfig paths
+
+You can enable `tsconfig` [paths](https://www.typescriptlang.org/docs/handbook/module-resolution.html#path-mapping)
+resolution with the following option:
+
+```yml
+custom:
+  serverlessPluginTypescript:
+    paths: true
+```

package.json

@@ -58,13 +58,15 @@
     "rimraf": "2.6.3",
     "standard-version": "^9.5.0",
     "ts-jest": "24.0.2",
+    "ts-node": "^10.9.1",
     "tslint": "5.14.0",
     "typescript": "^4.8.4"
   },
   "dependencies": {
     "fs-extra": "^7.0.1",
-    "globby": "^10.0.2",
-    "lodash": "^4.17.21"
+    "globby": "^11.1.0",
+    "lodash": "^4.17.21",
+    "typescript-transform-paths": "^3.4.6"
   },
   "peerDependencies": {
     "serverless": "2 || 3",

src/Serverless.d.ts

@@ -22,7 +22,8 @@ declare namespace Serverless {
       getAllLayers(): string[]
       custom?: {
         serverlessPluginTypescript?: {
-          tsConfigFileLocation: string
+          tsConfigFileLocation: string,
+          paths?: boolean
         }
       }
     }

src/index.ts

@@ -1,7 +1,7 @@
 import * as path from 'path'
 import * as fs from 'fs-extra'
 import * as _ from 'lodash'
-import * as globby from 'globby'
+import globby from 'globby'
 
 import * as typescript from './typescript'
 import { watchFiles } from './watchFiles'
@@ -187,7 +187,11 @@ export class TypeScriptPlugin {
 
     tsconfig.outDir = BUILD_FOLDER
 
-    const emitedFiles = await typescript.run(this.rootFileNames, tsconfig)
+    const emitedFiles = await typescript.run(
+        this.rootFileNames,
+        tsconfig,
+        { paths: this.serverless.service?.custom?.serverlessPluginTypescript?.paths ?? false }
+    )
     this.serverless.cli.log('Typescript compiled.')
     return emitedFiles
   }

src/typescript.ts

@@ -2,6 +2,7 @@ import * as ts from 'typescript'
 import * as fs from 'fs-extra'
 import * as _ from 'lodash'
 import * as path from 'path'
+import transformPaths from 'typescript-transform-paths';
 
 export function makeDefaultTypescriptConfig() {
   const defaultTypescriptConfig: ts.CompilerOptions = {
@@ -70,11 +71,17 @@ export function extractFileNames(cwd: string, provider: string, functions?: { [k
     })
 }
 
-export async function run(fileNames: string[], options: ts.CompilerOptions): Promise<string[]> {
+export async function run(fileNames: string[], options: ts.CompilerOptions, { paths = false }: { paths?: boolean } = {}): Promise<string[]> {
   options.listEmittedFiles = true
   const program = ts.createProgram(fileNames, options)
 
-  const emitResult = program.emit()
+  const emitResult = program.emit(
+      undefined,
+      undefined,
+      undefined,
+      false,
+      paths ? { before: [transformPaths(program, {}, { ts })] } : {}
+  )
 
   const allDiagnostics = ts.getPreEmitDiagnostics(program).concat(emitResult.diagnostics)
 

tsconfig.json

@@ -4,7 +4,8 @@
     "rootDir": ".",
     "target": "es6",
     "sourceMap": true,
-    "outDir": "dist"
+    "outDir": "dist",
+    "esModuleInterop": true
   },
   "exclude": [
     "node_modules"