feat(core): provide jest hoist plugin

Cargo.toml

@@ -16,10 +16,14 @@ serde_json = "1"
 swc = { git = "https://github.com/swc-project/swc" }
 swc_common = { git = "https://github.com/swc-project/swc", features = ["tty-emitter"] }
 swc_ecmascript = { git = "https://github.com/swc-project/swc", features = ["parser", "transforms"] }
+swc_ecma_visit = { git = "https://github.com/swc-project/swc" }
 
 [target.'cfg(all(unix, not(target_env = "musl")))'.dependencies]
 jemallocator = { version = "0.3", features = ["disable_initial_exec_tls"] }
 
+[target.'cfg(windows)'.dependencies]
+mimalloc = { version = "0.1" }
+
 [build-dependencies]
 napi-build = "0.2"
 

jest-test.js

@@ -0,0 +1,19 @@
+const { transformJest } = require('@swc-node/core')
+
+const fixture = `
+import { timer } from 'utils'
+
+jest.mock('./utils')
+
+describe('timer', () => {
+  it('timer should work', () => {
+    expect(timer()).toBe(1)
+  })
+})
+
+jest.unmock()
+`
+
+const { code } = transformJest(fixture, 'timer.spec.ts')
+
+console.log(code)

package.json

@@ -28,6 +28,7 @@
   },
   "scripts": {
     "build": "napi build --release --platform ./packages/core/swc",
+    "build:debug": "napi build --platform ./packages/core/swc",
     "format": "run-p format:md format:json format:source format:yml",
     "format:json": "prettier --parser json --write '**/*.json'",
     "format:md": "prettier --parser markdown --write './*.md' './packages/**/*.md'",

packages/core/index.d.ts

@@ -19,6 +19,15 @@ export function transformSync(
   map: string
 }
 
+export function transformJest(
+  source: string | Buffer,
+  path: string,
+  options?: Options,
+): {
+  code: string
+  map: string
+}
+
 export function transform(
   source: string | Buffer,
   path: string,

packages/core/index.js

@@ -43,7 +43,7 @@ module.exports = {
     const swcOptions = {
       filename: path,
       jsc: {
-        target: 'es2018',
+        target: opts.target || 'es2018',
         parser: {
           syntax: 'typescript',
           tsx: typeof opts.jsx !== 'undefined' ? opts.jsx : path.endsWith('.tsx'),
@@ -64,12 +64,38 @@ module.exports = {
     }
     return bindings.transformSync(source, path, Buffer.from(JSON.stringify(swcOptions)))
   },
+  transformJest: function transformJest(source, path, options) {
+    const opts = options == null ? {} : options
+    const swcOptions = {
+      filename: path,
+      jsc: {
+        target: opts.target || 'es2018',
+        parser: {
+          syntax: 'typescript',
+          tsx: typeof opts.jsx !== 'undefined' ? opts.jsx : path.endsWith('.tsx'),
+          decorators: Boolean(opts.experimentalDecorators),
+          dynamicImport: Boolean(opts.dynamicImport),
+        },
+        transform: {
+          legacyDecorator: Boolean(opts.experimentalDecorators),
+          decoratorMetadata: Boolean(opts.emitDecoratorMetadata),
+        },
+      },
+      isModule: true,
+      module: {
+        type: opts.module || 'commonjs',
+      },
+      sourceMaps: typeof opts.sourcemap === 'undefined' ? true : opts.sourcemap,
+      swcrc: false,
+    }
+    return bindings.transformJest(source, path, Buffer.from(JSON.stringify(swcOptions)))
+  },
   transform: function transform(source, path, options) {
     const opts = options == null ? {} : options
     const swcOptions = {
       filename: path,
       jsc: {
-        target: 'es2018',
+        target: opts.target || 'es2018',
         parser: {
           syntax: 'typescript',
           tsx: typeof opts.jsx !== 'undefined' ? opts.jsx : path.endsWith('.tsx'),

packages/jest/__test__/hoist-top-level.spec.ts

@@ -0,0 +1,41 @@
+import { transformJest } from '@swc-node/core'
+import test from 'ava'
+
+const BrorrwFromTsJest = `
+const foo = 'foo'
+console.log(foo)
+jest.enableAutomock()
+jest.disableAutomock()
+jest.mock('./foo')
+jest.mock('./foo/bar', () => 'bar')
+jest.unmock('./bar/foo').dontMock('./bar/bar')
+jest.deepUnmock('./foo')
+jest.mock('./foo').mock('./bar')
+const func = () => {
+  const bar = 'bar'
+  console.log(bar)
+  jest.unmock('./foo')
+  jest.mock('./bar')
+  jest.mock('./bar/foo', () => 'foo')
+  jest.unmock('./foo/bar')
+  jest.unmock('./bar/foo').dontMock('./bar/bar')
+  jest.deepUnmock('./bar')
+  jest.mock('./foo').mock('./bar')
+}
+const func2 = () => {
+  const bar = 'bar'
+  console.log(bar)
+  jest.mock('./bar')
+  jest.unmock('./foo/bar')
+  jest.mock('./bar/foo', () => 'foo')
+  jest.unmock('./foo')
+  jest.unmock('./bar/foo').dontMock('./bar/bar')
+  jest.deepUnmock('./bar')
+  jest.mock('./foo').mock('./bar')
+}
+`
+
+test('should hoist top level jest mock call', (t) => {
+  const { code } = transformJest(BrorrwFromTsJest, 'jest.spec.ts', { target: 'es2018', sourcemap: false })
+  t.snapshot(code)
+})

packages/jest/__test__/hoist-top-level.spec.ts.md

@@ -0,0 +1,46 @@
+# Snapshot report for `packages/jest/__test__/hoist-top-level.spec.ts`
+
+The actual snapshot is saved in `hoist-top-level.spec.ts.snap`.
+
+Generated by [AVA](https://avajs.dev).
+
+## should hoist top level jest mock call
+
+> Snapshot 1
+
+    `jest.enableAutomock();␊
+    jest.disableAutomock();␊
+    jest.mock('./foo');␊
+    jest.mock('./foo/bar', ()=>'bar'␊
+    );␊
+    jest.deepUnmock('./foo');␊
+    "use strict";␊
+    const foo = 'foo';␊
+    console.log(foo);␊
+    jest.unmock('./bar/foo').dontMock('./bar/bar');␊
+    jest.mock('./foo').mock('./bar');␊
+    const func = ()=>{␊
+        const bar = 'bar';␊
+        console.log(bar);␊
+        jest.unmock('./foo');␊
+        jest.mock('./bar');␊
+        jest.mock('./bar/foo', ()=>'foo'␊
+        );␊
+        jest.unmock('./foo/bar');␊
+        jest.unmock('./bar/foo').dontMock('./bar/bar');␊
+        jest.deepUnmock('./bar');␊
+        jest.mock('./foo').mock('./bar');␊
+    };␊
+    const func2 = ()=>{␊
+        const bar = 'bar';␊
+        console.log(bar);␊
+        jest.mock('./bar');␊
+        jest.unmock('./foo/bar');␊
+        jest.mock('./bar/foo', ()=>'foo'␊
+        );␊
+        jest.unmock('./foo');␊
+        jest.unmock('./bar/foo').dontMock('./bar/bar');␊
+        jest.deepUnmock('./bar');␊
+        jest.mock('./foo').mock('./bar');␊
+    };␊
+    `

packages/jest/index.js

@@ -1,11 +1,11 @@
-const { transformSync } = require('@swc-node/core')
+const { transformJest } = require('@swc-node/core')
 
 module.exports = {
   process(src, path, jestConfig) {
     const [, , transformOptions = {}] =
       (jestConfig.transform || []).find(([, transformerPath]) => transformerPath === __filename) || []
     if (/\.(t|j)sx?$/.test(path)) {
-      return transformSync(src, path, transformOptions)
+      return transformJest(src, path, transformOptions)
     }
     return src
   },

src/jest.rs

@@ -0,0 +1,90 @@
+use std::collections::HashSet;
+use std::path::PathBuf;
+use std::str::FromStr;
+
+use napi::{Error, Result, Status};
+use once_cell::sync::OnceCell;
+use swc::{config::Options, TransformOutput};
+use swc_common::{self, FileName};
+use swc_ecma_visit::Fold;
+use swc_ecmascript::ast::{Expr, ExprOrSuper, Module, ModuleItem, Stmt};
+
+use crate::get_compiler;
+
+const JEST: &'static str = "jest";
+
+static HOIST_METHODS: OnceCell<HashSet<&'static str>> = OnceCell::new();
+
+pub fn jest_transform(
+  source: String,
+  filename: &str,
+  register_options: &Options,
+) -> Result<TransformOutput> {
+  let c = get_compiler();
+  let fm = c.cm.new_source_file(
+    FileName::Real(
+      PathBuf::from_str(filename)
+        .map_err(|e| Error::new(Status::InvalidArg, format!("Invalid path {}", e)))?,
+    ),
+    source,
+  );
+
+  let jest_hoist_transformer = JestHoistTransformer;
+
+  c.process_js_with_custom_pass(fm, register_options, jest_hoist_transformer)
+    .map_err(|e| Error::new(Status::GenericFailure, format!("Process js failed {}", e)))
+}
+
+struct JestHoistTransformer;
+
+impl Fold for JestHoistTransformer {
+  fn fold_module(&mut self, mut n: Module) -> Module {
+    let hoist_methods = HOIST_METHODS.get_or_init(|| {
+      let mut hash_set = HashSet::with_capacity(5);
+      hash_set.insert("mock");
+      hash_set.insert("unmock");
+      hash_set.insert("enableAutomock");
+      hash_set.insert("disableAutomock");
+      hash_set.insert("deepUnmock");
+      hash_set
+    });
+    let mut new_body = Vec::with_capacity(n.body.len());
+    let mut stmts_to_hoist = Vec::with_capacity(n.body.len());
+    n.body.iter().for_each(|item| match item {
+      ModuleItem::Stmt(Stmt::Expr(expr_stmt)) => match &*expr_stmt.expr {
+        Expr::Call(call_expr) => {
+          if let ExprOrSuper::Expr(expr) = &call_expr.callee {
+            if let Expr::Member(member) = expr.as_ref() {
+              if let ExprOrSuper::Expr(expr) = &member.obj {
+                if let Expr::Ident(ident) = expr.as_ref() {
+                  let name = ident.sym.as_ref();
+                  let is_jest = name == JEST;
+                  if is_jest {
+                    if let Expr::Ident(ident) = member.prop.as_ref() {
+                      let func_name = ident.sym.as_ref();
+                      if hoist_methods.get(func_name).is_some() {
+                        stmts_to_hoist.insert(0, item.clone());
+                        return ();
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
+          new_body.push(item.clone());
+        }
+        _ => new_body.push(item.clone()),
+      },
+      _ => new_body.push(item.clone()),
+    });
+
+    for stmt in stmts_to_hoist {
+      new_body.insert(0, stmt);
+    }
+
+    n.body = new_body;
+
+    n
+  }
+}