[now-build-utils] Add functions property (#3213)

This updates `@now/build-utils` to add support for the function property including types and tests.

Related: [PRODUCT-27]

[PRODUCT-27]: https://zeit.atlassian.net/browse/PRODUCT-27

packages/now-build-utils/src/detect-builders.ts

@@ -1,5 +1,5 @@
-import { PackageJson, Builder, Config } from './types';
 import minimatch from 'minimatch';
+import { PackageJson, Builder, Config, BuilderFunctions } from './types';
 
 interface ErrorResponse {
   code: string;
@@ -8,6 +8,7 @@ interface ErrorResponse {
 
 interface Options {
   tag?: 'canary' | 'latest' | string;
+  functions?: BuilderFunctions;
 }
 
 const src = 'package.json';
@@ -21,21 +22,25 @@ const MISSING_BUILD_SCRIPT_ERROR: ErrorResponse = {
 };
 
 // Static builders are special cased in `@now/static-build`
-function getBuilders(): Map<string, Builder> {
+function getBuilders({ tag }: Options = {}): Map<string, Builder> {
+  const withTag = tag ? `@${tag}` : '';
+
   return new Map<string, Builder>([
-    ['next', { src, use: '@now/next', config }],
+    ['next', { src, use: `@now/next${withTag}`, config }],
   ]);
 }
 
 // Must be a function to ensure that the returned
 // object won't be a reference
-function getApiBuilders(): Builder[] {
+function getApiBuilders({ tag }: Options = {}): Builder[] {
+  const withTag = tag ? `@${tag}` : '';
+
   return [
-    { src: 'api/**/*.js', use: '@now/node', config },
-    { src: 'api/**/*.ts', use: '@now/node', config },
-    { src: 'api/**/*.go', use: '@now/go', config },
-    { src: 'api/**/*.py', use: '@now/python', config },
-    { src: 'api/**/*.rb', use: '@now/ruby', config },
+    { src: 'api/**/*.js', use: `@now/node${withTag}`, config },
+    { src: 'api/**/*.ts', use: `@now/node${withTag}`, config },
+    { src: 'api/**/*.go', use: `@now/go${withTag}`, config },
+    { src: 'api/**/*.py', use: `@now/python${withTag}`, config },
+    { src: 'api/**/*.rb', use: `@now/ruby${withTag}`, config },
   ];
 }
 
@@ -48,13 +53,50 @@ function hasBuildScript(pkg: PackageJson | undefined) {
   return Boolean(scripts && scripts['build']);
 }
 
-async function detectBuilder(pkg: PackageJson): Promise<Builder> {
-  for (const [dependency, builder] of getBuilders()) {
+function getFunctionBuilder(
+  file: string,
+  prevBuilder: Builder | undefined,
+  { functions = {} }: Options
+) {
+  const key = Object.keys(functions).find(
+    k => minimatch(file, k) || file === k
+  );
+  const fn = key ? functions[key] : undefined;
+
+  if (!fn || (!fn.runtime && !prevBuilder)) {
+    return prevBuilder;
+  }
+
+  const src = (prevBuilder && prevBuilder.src) || file;
+  const use = fn.runtime || (prevBuilder && prevBuilder.use);
+  const config: Config = Object.assign({}, prevBuilder && prevBuilder.config);
+
+  if (!use) {
+    return prevBuilder;
+  }
+
+  if (fn.memory) {
+    config.memory = fn.memory;
+  }
+
+  if (fn.maxDuration) {
+    config.maxDuration = fn.maxDuration;
+  }
+
+  return { use, src, config };
+}
+
+async function detectFrontBuilder(
+  pkg: PackageJson,
+  options: Options
+): Promise<Builder> {
+  for (const [dependency, builder] of getBuilders(options)) {
     const deps = Object.assign({}, pkg.dependencies, pkg.devDependencies);
+    const fnBuilder = getFunctionBuilder('package.json', builder, options);
 
     // Return the builder when a dependency matches
     if (deps[dependency]) {
-      return builder;
+      return fnBuilder || builder;
     }
   }
 
@@ -91,16 +133,19 @@ export function sortFiles(fileA: string, fileB: string) {
   return fileA.localeCompare(fileB);
 }
 
-async function detectApiBuilders(files: string[]): Promise<Builder[]> {
+async function detectApiBuilders(
+  files: string[],
+  options: Options
+): Promise<Builder[]> {
   const builds = files
     .sort(sortFiles)
     .filter(ignoreApiFilter)
     .map(file => {
-      const result = getApiBuilders().find(({ src }): boolean =>
-        minimatch(file, src)
+      const apiBuilder = getApiBuilders(options).find(b =>
+        minimatch(file, b.src)
       );
-
-      return result ? { ...result, src: file } : null;
+      const fnBuilder = getFunctionBuilder(file, apiBuilder, options);
+      return fnBuilder ? { ...fnBuilder, src: file } : null;
     });
 
   const finishedBuilds = builds.filter(Boolean);
@@ -114,11 +159,9 @@ async function checkConflictingFiles(
   builders: Builder[]
 ): Promise<ErrorResponse | null> {
   // For Next.js
-  if (builders.some(builder => builder.use.startsWith('@now/next'))) {
+  if (builders.some(b => b.use.startsWith('@now/next'))) {
     const hasApiPages = files.some(file => file.startsWith('pages/api/'));
-    const hasApiBuilders = builders.some(builder =>
-      builder.src.startsWith('api/')
-    );
+    const hasApiBuilders = builders.some(b => b.src.startsWith('api/'));
 
     if (hasApiPages && hasApiBuilders) {
       return {
@@ -137,7 +180,7 @@ async function checkConflictingFiles(
 export async function detectBuilders(
   files: string[],
   pkg?: PackageJson | undefined | null,
-  options?: Options
+  options: Options = {}
 ): Promise<{
   builders: Builder[] | null;
   errors: ErrorResponse[] | null;
@@ -147,10 +190,10 @@ export async function detectBuilders(
   const warnings: ErrorResponse[] = [];
 
   // Detect all builders for the `api` directory before anything else
-  let builders = await detectApiBuilders(files);
+  const builders = await detectApiBuilders(files, options);
 
   if (pkg && hasBuildScript(pkg)) {
-    builders.push(await detectBuilder(pkg));
+    builders.push(await detectFrontBuilder(pkg, options));
 
     const conflictError = await checkConflictingFiles(files, builders);
 
@@ -187,25 +230,6 @@ export async function detectBuilders(
     }
   }
 
-  // Change the tag for the builders
-  if (builders && builders.length) {
-    const tag = options && options.tag;
-
-    if (tag) {
-      builders = builders.map((originBuilder: Builder) => {
-        // Copy builder to make sure it is not a reference
-        const builder = { ...originBuilder };
-
-        // @now/static has no canary builder
-        if (builder.use !== '@now/static') {
-          builder.use = `${builder.use}@${tag}`;
-        }
-
-        return builder;
-      });
-    }
-  }
-
   return {
     builders: builders.length ? builders : null,
     errors: errors.length ? errors : null,

packages/now-build-utils/src/types.ts

@@ -49,6 +49,8 @@ export interface Config {
   debug?: boolean;
   zeroConfig?: boolean;
   import?: { [key: string]: string };
+  memory?: number;
+  maxDuration?: number;
 }
 
 export interface Meta {
@@ -308,3 +310,11 @@ export interface Builder {
   src: string;
   config?: Config;
 }
+
+export interface BuilderFunctions {
+  [key: string]: {
+    memory?: number;
+    maxDuration?: number;
+    runtime?: string;
+  };
+}

packages/now-build-utils/test/unit.test.js

@@ -444,6 +444,50 @@ it('Test `detectBuilders`', async () => {
     expect(builders[1].use).toBe('@now/static');
     expect(builders[1].src).toBe('!{api/**,package.json}');
   }
+
+  {
+    // extend with functions
+    const pkg = {
+      scripts: { build: 'next build' },
+      dependencies: { next: '9.0.0' },
+    };
+    const functions = {
+      'api/users/*.ts': {
+        runtime: 'my-custom-runtime-package',
+      },
+      'api/teams/members.ts': {
+        memory: 128,
+        maxDuration: 10,
+      },
+      'package.json': {
+        memory: 3008,
+        runtime: '@now/next@canary',
+      },
+    };
+    const files = [
+      'pages/index.js',
+      'api/users/[id].ts',
+      'api/teams/members.ts',
+    ];
+    const { builders } = await detectBuilders(files, pkg, { functions });
+
+    expect(builders.length).toBe(3);
+    expect(builders[0]).toEqual({
+      src: 'api/teams/members.ts',
+      use: '@now/node',
+      config: { zeroConfig: true, memory: 128, maxDuration: 10 },
+    });
+    expect(builders[1]).toEqual({
+      src: 'api/users/[id].ts',
+      use: 'my-custom-runtime-package',
+      config: { zeroConfig: true },
+    });
+    expect(builders[2]).toEqual({
+      src: 'package.json',
+      use: '@now/next@canary',
+      config: { zeroConfig: true, memory: 3008 },
+    });
+  }
 });
 
 it('Test `detectRoutes`', async () => {