feat: Support user defined tsconfig paths (serverless#205)

Author: Scotsoo

README.md

@@ -61,6 +61,14 @@ The default `tsconfig.json` file used by the plugin looks like this:
 
 All files from `package/include` will be included in the final build file. See [Exclude/Include](https://serverless.com/framework/docs/providers/aws/guide/packaging#exclude--include)
 
+### Non-standard tsconfig.json locations
+Override what tsconfig.json to use with the following snippet in your severless.yaml
+```
+custom:
+  serverlessPluginTypescript:
+    tsConfigFileLocation: './tsconfig.build.json'
+
+```
 
 ## Usage
 

src/Serverless.d.ts

@@ -17,6 +17,11 @@ declare namespace Serverless {
       }
       package: Serverless.Package
       getAllFunctions(): string[]
+      custom?: {
+        serverlessPluginTypescript?: {
+          tsConfigFileLocation: string
+        }
+      }
     }
 
     pluginManager: PluginManager

src/index.ts

@@ -145,9 +145,16 @@ export class TypeScriptPlugin {
       // Fake service path so that serverless will know what to zip
       this.serverless.config.servicePath = path.join(this.originalServicePath, BUILD_FOLDER)
     }
-
+    let tsConfigFileLocation: string | undefined
+    if (
+      this.serverless.service.custom !== undefined
+      && this.serverless.service.custom.serverlessPluginTypescript !== undefined
+    ) {
+      tsConfigFileLocation = this.serverless.service.custom.serverlessPluginTypescript.tsConfigFileLocation
+    }
     const tsconfig = typescript.getTypescriptConfig(
       this.originalServicePath,
+      tsConfigFileLocation,
       this.isWatching ? null : this.serverless.cli
     )
 

src/typescript.ts

@@ -112,16 +112,20 @@ export function getSourceFiles(
 
 export function getTypescriptConfig(
   cwd: string,
+  tsConfigFileLocation: string = 'tsconfig.json',
   logger?: { log: (str: string) => void }
 ): ts.CompilerOptions {
-  const configFilePath = path.join(cwd, 'tsconfig.json')
+  const configFilePath = path.join(cwd, tsConfigFileLocation)
 
   if (fs.existsSync(configFilePath)) {
-
     const configFileText = fs.readFileSync(configFilePath).toString()
     const result = ts.parseConfigFileTextToJson(configFilePath, configFileText)
     if (result.error) {
-      throw new Error(JSON.stringify(result.error))
+      try {
+        throw new Error(JSON.stringify(result.error))
+      } catch (err) {
+        throw new Error('Invalid TSConfig file - is this file JSON format?')
+      }
     }
 
     const configParseResult = ts.parseJsonConfigFileContent(result.config, ts.sys, path.dirname(configFilePath))
@@ -130,7 +134,7 @@ export function getTypescriptConfig(
     }
 
     if (logger) {
-      logger.log(`Using local tsconfig.json`)
+      logger.log(`Using local tsconfig.json - ${tsConfigFileLocation}`)
     }
 
     // disallow overrriding rootDir

tests/assets/tsconfigs/index.ts

@@ -0,0 +1 @@
+export const test = 'example'

tests/assets/tsconfigs/tsconfig.default.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "preserveConstEnums": true,
+    "strictNullChecks": true,
+    "sourceMap": true,
+    "allowJs": true,
+    "target": "es5",
+    "outDir": ".build",
+    "moduleResolution": "node",
+    "lib": ["es2015"],
+    "rootDir": "./"
+  }
+}

tests/assets/tsconfigs/tsconfig.invalid.json

@@ -0,0 +1 @@
+This is not a tsconfig.json file

tests/typescript.getTypescriptConfig.test.ts

@@ -1,4 +1,5 @@
 import {getTypescriptConfig, makeDefaultTypescriptConfig} from '../src/typescript'
+import * as path from 'path'
 
 describe('getTypescriptConfig', () => {
     it(`returns default typescript configuration if the one provided doesn't exist`, () => {
@@ -8,4 +9,39 @@ describe('getTypescriptConfig', () => {
             makeDefaultTypescriptConfig()
         )
     })
-})
+
+    it(`returns default typescript configuration if the one provided doesn't exist when tsConfigFileLocation provided`, () => {
+        expect(
+            getTypescriptConfig(process.cwd(), './tests/assets/tsconfigs/tsconfig.nonexistent.json'),
+        ).toEqual(
+            makeDefaultTypescriptConfig()
+        )
+    })
+
+    it(`returns custom typescript configuration if tsConfigFileLocation provided`, () => {
+        const tsconfigDir = path.join(process.cwd(), './tests/assets/tsconfigs/')
+        expect(
+            getTypescriptConfig(tsconfigDir, 'tsconfig.default.json'),
+        ).toEqual({
+            allowJs: true,
+            configFilePath: undefined,
+            lib: ["lib.es2015.d.ts"],
+            moduleResolution: 2,
+            outDir: path.join(tsconfigDir, '.build'),
+            preserveConstEnums: true,
+            rootDir: tsconfigDir,
+            sourceMap: true,
+            strictNullChecks: true,
+            target: 1
+        })
+    })
+
+    it(`throws error if configuration from tsConfigFileLocation is invalid`, () => {
+        expect.assertions(1)
+        try {
+            getTypescriptConfig(process.cwd(), './tests/assets/tsconfigs/tsconfig.invalid.json')
+        } catch (e) {
+            expect(e.message).toBe('Invalid TSConfig file - is this file JSON format?')
+        }
+    })
+})