From df1bb80803f2c75e122834dfae217d08a75f9f82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Tue, 5 Apr 2022 14:26:31 -0400
Subject: [PATCH 1/8] extract purity test

---
 packages/babel-traverse/test/path/isPure.js | 37 +++++++++++++++++++++
 packages/babel-traverse/test/scope.js       | 35 +------------------
 2 files changed, 38 insertions(+), 34 deletions(-)
 create mode 100644 packages/babel-traverse/test/path/isPure.js

diff --git a/packages/babel-traverse/test/path/isPure.js b/packages/babel-traverse/test/path/isPure.js
new file mode 100644
index 000000000000..97233e9b5a4d
--- /dev/null
+++ b/packages/babel-traverse/test/path/isPure.js
@@ -0,0 +1,37 @@
+import { parse } from "@babel/parser";
+
+import _traverse from "../../lib/index.js";
+const traverse = _traverse.default;
+
+function getPath(code, options) {
+  const ast = parse(code, options);
+  let path;
+  traverse(ast, {
+    Program: function (_path) {
+      path = _path;
+      _path.stop();
+    },
+  });
+  return path;
+}
+
+describe("isPure() returns true", () => {
+  it.each([
+    ["({ x: 1, foo() { return 1 } })", "body.0.expression"],
+    ["let a = 1; `${a}`", "body.1.expression"],
+    ["String.raw`foo`", "body.0.expression"],
+  ])(`NodePath(%p).get(%p).isPure() should be true`, (input, pathSpec) => {
+    expect(getPath(input).get(pathSpec).isPure()).toBe(true);
+  });
+});
+
+describe("isPure() returns false", () => {
+  it.each([
+    ["class X { get foo() { return 1 } }", "body.0.expression"],
+    ["`${a}`", "body.0.expression"],
+    ["let a = 1; `${a++}`", "body.1.expression"],
+    ["tagged`foo`", "body.0.expression"],
+  ])(`NodePath(%p).get(%p).isPure() should be false`, (input, pathSpec) => {
+    expect(getPath(input).get(pathSpec).isPure()).toBe(false);
+  });
+});
diff --git a/packages/babel-traverse/test/scope.js b/packages/babel-traverse/test/scope.js
index e5c2dfaa9611..375089129e16 100644
--- a/packages/babel-traverse/test/scope.js
+++ b/packages/babel-traverse/test/scope.js
@@ -365,39 +365,6 @@ describe("scope", () => {
       ).toBe(false);
     });
 
-    it("purity", function () {
-      expect(
-        getPath("({ x: 1, foo() { return 1 } })")
-          .get("body")[0]
-          .get("expression")
-          .isPure(),
-      ).toBeTruthy();
-      expect(
-        getPath("class X { get foo() { return 1 } }")
-          .get("body")[0]
-          .get("expression")
-          .isPure(),
-      ).toBeFalsy();
-      expect(
-        getPath("`${a}`").get("body")[0].get("expression").isPure(),
-      ).toBeFalsy();
-      expect(
-        getPath("let a = 1; `${a}`").get("body")[1].get("expression").isPure(),
-      ).toBeTruthy();
-      expect(
-        getPath("let a = 1; `${a++}`")
-          .get("body")[1]
-          .get("expression")
-          .isPure(),
-      ).toBeFalsy();
-      expect(
-        getPath("tagged`foo`").get("body")[0].get("expression").isPure(),
-      ).toBeFalsy();
-      expect(
-        getPath("String.raw`foo`").get("body")[0].get("expression").isPure(),
-      ).toBeTruthy();
-    });
-
     test("label", function () {
       expect(getPath("foo: { }").scope.getBinding("foo")).toBeUndefined();
       expect(getPath("foo: { }").scope.getLabel("foo").type).toBe(
@@ -542,7 +509,7 @@ describe("scope", () => {
       path.scope.crawl();
       path.scope.crawl();
 
-      expect(path.scope.references._jsx).toBeTruthy();
+      expect(path.scope.references._jsx).toBe(true);
     });
 
     test("generateUid collision check after re-crawling", function () {

From ac872bbbc8ae1d4fe402fb9c65576b5fde01a737 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Tue, 5 Apr 2022 15:56:00 -0400
Subject: [PATCH 2/8] update scope.isPure

---
 packages/babel-traverse/src/scope/index.ts  | 45 +++++++++--
 packages/babel-traverse/test/path/isPure.js | 86 +++++++++++++++++----
 2 files changed, 112 insertions(+), 19 deletions(-)

diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 7170b5acacca..4a5b6473beaa 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -42,6 +42,13 @@ import {
   unaryExpression,
   variableDeclaration,
   variableDeclarator,
+  isRecordExpression,
+  isTupleExpression,
+  isClassAccessorProperty,
+  isObjectProperty,
+  isDecorator,
+  isTopicReference,
+  isMetaProperty,
 } from "@babel/types";
 import type * as t from "@babel/types";
 import { scope as scopeCache } from "../cache";
@@ -535,7 +542,7 @@ export default class Scope {
    */
 
   isStatic(node: t.Node): boolean {
-    if (isThisExpression(node) || isSuper(node)) {
+    if (isThisExpression(node) || isSuper(node) || isTopicReference(node)) {
       return true;
     }
 
@@ -823,10 +830,21 @@ export default class Scope {
       if (!binding) return false;
       if (constantsOnly) return binding.constant;
       return true;
+    } else if (
+      isThisExpression(node) ||
+      isMetaProperty(node) ||
+      isTopicReference(node)
+    ) {
+      return true;
     } else if (isClass(node)) {
       if (node.superClass && !this.isPure(node.superClass, constantsOnly)) {
         return false;
       }
+      if (node.decorators) {
+        for (const decorator of node.decorators) {
+          if (!this.isPure(decorator, constantsOnly)) return false;
+        }
+      }
       return this.isPure(node.body, constantsOnly);
     } else if (isClassBody(node)) {
       for (const method of node.body) {
@@ -838,24 +856,39 @@ export default class Scope {
         this.isPure(node.left, constantsOnly) &&
         this.isPure(node.right, constantsOnly)
       );
-    } else if (isArrayExpression(node)) {
+    } else if (isArrayExpression(node) || isTupleExpression(node)) {
       for (const elem of node.elements) {
-        if (!this.isPure(elem, constantsOnly)) return false;
+        if (elem !== null && !this.isPure(elem, constantsOnly)) return false;
       }
       return true;
-    } else if (isObjectExpression(node)) {
+    } else if (isObjectExpression(node) || isRecordExpression(node)) {
       for (const prop of node.properties) {
         if (!this.isPure(prop, constantsOnly)) return false;
       }
       return true;
+    } else if (isDecorator(node)) {
+      return this.isPure(node.expression, constantsOnly);
     } else if (isMethod(node)) {
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
       if (node.kind === "get" || node.kind === "set") return false;
+      if (node.decorators) {
+        for (const decorator of node.decorators) {
+          if (!this.isPure(decorator, constantsOnly)) return false;
+        }
+      }
       return true;
-    } else if (isProperty(node)) {
+    } else if (isProperty(node) || isClassAccessorProperty(node)) {
       // @ts-expect-error todo(flow->ts): computed in not present on private properties
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
-      return this.isPure(node.value, constantsOnly);
+      if (node.decorators) {
+        for (const decorator of node.decorators) {
+          if (!this.isPure(decorator, constantsOnly)) return false;
+        }
+      }
+      if (isObjectProperty(node) || node.static) {
+        return this.isPure(node.value, constantsOnly);
+      }
+      return true;
     } else if (isUnaryExpression(node)) {
       return this.isPure(node.argument, constantsOnly);
     } else if (isTaggedTemplateExpression(node)) {
diff --git a/packages/babel-traverse/test/path/isPure.js b/packages/babel-traverse/test/path/isPure.js
index 97233e9b5a4d..1b64fa87036e 100644
--- a/packages/babel-traverse/test/path/isPure.js
+++ b/packages/babel-traverse/test/path/isPure.js
@@ -3,8 +3,15 @@ import { parse } from "@babel/parser";
 import _traverse from "../../lib/index.js";
 const traverse = _traverse.default;
 
-function getPath(code, options) {
-  const ast = parse(code, options);
+function getPath(code) {
+  const ast = parse(code, {
+    plugins: [
+      ["decorators", { version: "2021-12", decoratorsBeforeExport: true }],
+      ["recordAndTuple", { syntaxType: "hash" }],
+      "decoratorAutoAccessors",
+      ["pipelineOperator", { proposal: "hack", topicToken: "%" }],
+    ],
+  });
   let path;
   traverse(ast, {
     Program: function (_path) {
@@ -17,21 +24,74 @@ function getPath(code, options) {
 
 describe("isPure() returns true", () => {
   it.each([
-    ["({ x: 1, foo() { return 1 } })", "body.0.expression"],
-    ["let a = 1; `${a}`", "body.1.expression"],
-    ["String.raw`foo`", "body.0.expression"],
-  ])(`NodePath(%p).get(%p).isPure() should be true`, (input, pathSpec) => {
-    expect(getPath(input).get(pathSpec).isPure()).toBe(true);
+    "class C { [0]() {} }",
+    "class C extends class {} {}",
+    "class C { static accessor x = 1 }",
+    "class C { accessor x = f() }",
+    "class C { #x = f() }",
+    "@dec class C {}; function dec () {}",
+    "class C { static target = new.target }",
+  ])(`NodePath(%p).get("body.0").isPure() should be true`, input => {
+    const path = getPath(input).get("body.0");
+    expect(path.node).toBeTruthy();
+    expect(path.isPure()).toBe(true);
   });
+
+  it.each([
+    "({ x: 1, foo() { return 1 } })",
+    "String.raw`foo`",
+    `"a" + "b"`,
+    `[function () {}]`,
+    `#{ 0: 0, 1n: 1, two: "two"}`,
+    `#[0, 1n, "2", \`3\`]`,
+    `[,]`,
+    `-1 || void 0`,
+    `null ?? (true && false)`,
+    `this`,
+  ])(`NodePath(%p).get("body.0.expression").isPure() should be true`, input => {
+    const path = getPath(input).get("body.0.expression");
+    expect(path.node).toBeTruthy();
+    expect(path.isPure()).toBe(true);
+  });
+
+  it.each(["let a = 1; `${a}`", `let a = 1; a |> % + %`])(
+    `NodePath(%p).get("body.1.expression").isPure() should be true`,
+    input => {
+      const path = getPath(input).get("body.1.expression");
+      expect(path.node).toBeTruthy();
+      expect(path.isPure()).toBe(true);
+    },
+  );
 });
 
 describe("isPure() returns false", () => {
   it.each([
-    ["class X { get foo() { return 1 } }", "body.0.expression"],
-    ["`${a}`", "body.0.expression"],
-    ["let a = 1; `${a++}`", "body.1.expression"],
-    ["tagged`foo`", "body.0.expression"],
-  ])(`NodePath(%p).get(%p).isPure() should be false`, (input, pathSpec) => {
-    expect(getPath(input).get(pathSpec).isPure()).toBe(false);
+    "class X { get foo() { return 1 } }",
+    "@dec() class X {}",
+    "class C { @dec foo() {} }",
+    "class C { static {} }",
+    "class C extends class { [f()] } {}",
+  ])(`NodePath(%p).get("body.0").isPure() should be false`, input => {
+    const path = getPath(input).get("body.0");
+    expect(path.node).toBeTruthy();
+    expect(path.isPure()).toBe(false);
   });
+
+  it.each(["`${a}`", "tagged`foo`"])(
+    `NodePath(%p).get("body.0.expression").isPure() should be false`,
+    input => {
+      const path = getPath(input).get("body.0.expression");
+      expect(path.node).toBeTruthy();
+      expect(path.isPure()).toBe(false);
+    },
+  );
+
+  it.each(["let a = 1; `${a++}`"])(
+    `NodePath(%p).get("body.1.expression").isPure() should be false`,
+    input => {
+      const path = getPath(input).get("body.1.expression");
+      expect(path.node).toBeTruthy();
+      expect(path.isPure()).toBe(false);
+    },
+  );
 });

From a9547089d40e22cef705f75e2e1201cdd22f0eef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Tue, 5 Apr 2022 16:10:59 -0400
Subject: [PATCH 3/8] update test fixtures

---
 .../output.js                                             | 8 ++------
 .../hack-caret/pipe-body-with-nested-pipe/output.js       | 2 +-
 .../output.js                                             | 8 ++------
 .../hack-double-at/pipe-body-with-nested-pipe/output.js   | 2 +-
 .../output.js                                             | 8 ++------
 .../pipe-body-with-nested-pipe/output.js                  | 2 +-
 .../output.js                                             | 8 ++------
 .../hack-hash/pipe-body-with-nested-pipe/output.js        | 2 +-
 .../output.js                                             | 8 ++------
 .../hack-percent/pipe-body-with-nested-pipe/output.js     | 2 +-
 10 files changed, 15 insertions(+), 35 deletions(-)

diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
index de6a062dd636..fced893dbedc 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
@@ -1,8 +1,4 @@
-var _ref2;
+var _ref;
 
-const result = (_ref2 = Math.pow(5, 2), [1, 2, 3].map(n => {
-  var _ref;
-
-  return _ref = (n + _ref2) * 2, `${_ref} apples`.toUpperCase();
-}).join());
+const result = (_ref = Math.pow(5, 2), [1, 2, 3].map(n => `${(n + _ref) * 2} apples`.toUpperCase()).join());
 expect(result).toEqual('52 APPLES,54 APPLES,56 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-nested-pipe/output.js
index c877ba76e3ab..ada1ebb0ab10 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-caret/pipe-body-with-nested-pipe/output.js
@@ -1,4 +1,4 @@
 var _ref;
 
-const result = (_ref = Math.pow(5, 2) + 1, `${_ref} apples`.toUpperCase());
+const result = (_ref = Math.pow(5, 2), `${_ref + 1} apples`.toUpperCase());
 expect(result).toEqual('26 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-arrow-function-and-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-arrow-function-and-nested-pipe/output.js
index de6a062dd636..fced893dbedc 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-arrow-function-and-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-arrow-function-and-nested-pipe/output.js
@@ -1,8 +1,4 @@
-var _ref2;
+var _ref;
 
-const result = (_ref2 = Math.pow(5, 2), [1, 2, 3].map(n => {
-  var _ref;
-
-  return _ref = (n + _ref2) * 2, `${_ref} apples`.toUpperCase();
-}).join());
+const result = (_ref = Math.pow(5, 2), [1, 2, 3].map(n => `${(n + _ref) * 2} apples`.toUpperCase()).join());
 expect(result).toEqual('52 APPLES,54 APPLES,56 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-nested-pipe/output.js
index c877ba76e3ab..ada1ebb0ab10 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-at/pipe-body-with-nested-pipe/output.js
@@ -1,4 +1,4 @@
 var _ref;
 
-const result = (_ref = Math.pow(5, 2) + 1, `${_ref} apples`.toUpperCase());
+const result = (_ref = Math.pow(5, 2), `${_ref + 1} apples`.toUpperCase());
 expect(result).toEqual('26 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
index de6a062dd636..fced893dbedc 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-arrow-function-and-nested-pipe/output.js
@@ -1,8 +1,4 @@
-var _ref2;
+var _ref;
 
-const result = (_ref2 = Math.pow(5, 2), [1, 2, 3].map(n => {
-  var _ref;
-
-  return _ref = (n + _ref2) * 2, `${_ref} apples`.toUpperCase();
-}).join());
+const result = (_ref = Math.pow(5, 2), [1, 2, 3].map(n => `${(n + _ref) * 2} apples`.toUpperCase()).join());
 expect(result).toEqual('52 APPLES,54 APPLES,56 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-nested-pipe/output.js
index c877ba76e3ab..ada1ebb0ab10 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-double-caret/pipe-body-with-nested-pipe/output.js
@@ -1,4 +1,4 @@
 var _ref;
 
-const result = (_ref = Math.pow(5, 2) + 1, `${_ref} apples`.toUpperCase());
+const result = (_ref = Math.pow(5, 2), `${_ref + 1} apples`.toUpperCase());
 expect(result).toEqual('26 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-arrow-function-and-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-arrow-function-and-nested-pipe/output.js
index de6a062dd636..fced893dbedc 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-arrow-function-and-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-arrow-function-and-nested-pipe/output.js
@@ -1,8 +1,4 @@
-var _ref2;
+var _ref;
 
-const result = (_ref2 = Math.pow(5, 2), [1, 2, 3].map(n => {
-  var _ref;
-
-  return _ref = (n + _ref2) * 2, `${_ref} apples`.toUpperCase();
-}).join());
+const result = (_ref = Math.pow(5, 2), [1, 2, 3].map(n => `${(n + _ref) * 2} apples`.toUpperCase()).join());
 expect(result).toEqual('52 APPLES,54 APPLES,56 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-nested-pipe/output.js
index c877ba76e3ab..ada1ebb0ab10 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-hash/pipe-body-with-nested-pipe/output.js
@@ -1,4 +1,4 @@
 var _ref;
 
-const result = (_ref = Math.pow(5, 2) + 1, `${_ref} apples`.toUpperCase());
+const result = (_ref = Math.pow(5, 2), `${_ref + 1} apples`.toUpperCase());
 expect(result).toEqual('26 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-arrow-function-and-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-arrow-function-and-nested-pipe/output.js
index de6a062dd636..fced893dbedc 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-arrow-function-and-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-arrow-function-and-nested-pipe/output.js
@@ -1,8 +1,4 @@
-var _ref2;
+var _ref;
 
-const result = (_ref2 = Math.pow(5, 2), [1, 2, 3].map(n => {
-  var _ref;
-
-  return _ref = (n + _ref2) * 2, `${_ref} apples`.toUpperCase();
-}).join());
+const result = (_ref = Math.pow(5, 2), [1, 2, 3].map(n => `${(n + _ref) * 2} apples`.toUpperCase()).join());
 expect(result).toEqual('52 APPLES,54 APPLES,56 APPLES');
diff --git a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-nested-pipe/output.js b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-nested-pipe/output.js
index c877ba76e3ab..ada1ebb0ab10 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-nested-pipe/output.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/test/fixtures/hack-percent/pipe-body-with-nested-pipe/output.js
@@ -1,4 +1,4 @@
 var _ref;
 
-const result = (_ref = Math.pow(5, 2) + 1, `${_ref} apples`.toUpperCase());
+const result = (_ref = Math.pow(5, 2), `${_ref + 1} apples`.toUpperCase());
 expect(result).toEqual('26 APPLES');

From 723318f169adc793cf6d51725728ab1fcf4b4d51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Wed, 6 Apr 2022 10:17:31 -0400
Subject: [PATCH 4/8] mark decorated class(elements) as impure

---
 packages/babel-traverse/src/scope/index.ts  | 23 ++++++++-------------
 packages/babel-traverse/test/path/isPure.js | 11 +++++-----
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 4a5b6473beaa..4d8a60335257 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -840,10 +840,8 @@ export default class Scope {
       if (node.superClass && !this.isPure(node.superClass, constantsOnly)) {
         return false;
       }
-      if (node.decorators) {
-        for (const decorator of node.decorators) {
-          if (!this.isPure(decorator, constantsOnly)) return false;
-        }
+      if (node.decorators?.length > 0) {
+        return false;
       }
       return this.isPure(node.body, constantsOnly);
     } else if (isClassBody(node)) {
@@ -870,23 +868,20 @@ export default class Scope {
       return this.isPure(node.expression, constantsOnly);
     } else if (isMethod(node)) {
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
-      if (node.kind === "get" || node.kind === "set") return false;
-      if (node.decorators) {
-        for (const decorator of node.decorators) {
-          if (!this.isPure(decorator, constantsOnly)) return false;
-        }
+      if (node.decorators?.length > 0) {
+        return false;
       }
       return true;
     } else if (isProperty(node) || isClassAccessorProperty(node)) {
       // @ts-expect-error todo(flow->ts): computed in not present on private properties
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
-      if (node.decorators) {
-        for (const decorator of node.decorators) {
-          if (!this.isPure(decorator, constantsOnly)) return false;
-        }
+      if (node.decorators?.length > 0) {
+        return false;
       }
       if (isObjectProperty(node) || node.static) {
-        return this.isPure(node.value, constantsOnly);
+        if (node.value !== null && !this.isPure(node.value, constantsOnly)) {
+          return false;
+        }
       }
       return true;
     } else if (isUnaryExpression(node)) {
diff --git a/packages/babel-traverse/test/path/isPure.js b/packages/babel-traverse/test/path/isPure.js
index 1b64fa87036e..6d32a209618e 100644
--- a/packages/babel-traverse/test/path/isPure.js
+++ b/packages/babel-traverse/test/path/isPure.js
@@ -26,11 +26,10 @@ describe("isPure() returns true", () => {
   it.each([
     "class C { [0]() {} }",
     "class C extends class {} {}",
-    "class C { static accessor x = 1 }",
-    "class C { accessor x = f() }",
-    "class C { #x = f() }",
-    "@dec class C {}; function dec () {}",
+    "class C { static accessor x = 1; accessor y = f() }",
+    "class C { #x = f(); static #y }",
     "class C { static target = new.target }",
+    "class X { get foo() { return 1 } set foo(v) {} }",
   ])(`NodePath(%p).get("body.0").isPure() should be true`, input => {
     const path = getPath(input).get("body.0");
     expect(path.node).toBeTruthy();
@@ -66,9 +65,11 @@ describe("isPure() returns true", () => {
 
 describe("isPure() returns false", () => {
   it.each([
-    "class X { get foo() { return 1 } }",
     "@dec() class X {}",
+    "@dec class C {}; function dec () {}",
     "class C { @dec foo() {} }",
+    "class C { @dec foo }",
+    "class C { @dec accessor foo = 1 }",
     "class C { static {} }",
     "class C extends class { [f()] } {}",
   ])(`NodePath(%p).get("body.0").isPure() should be false`, input => {

From 5da9f64215455ee833261aa75270a39471942502 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Wed, 6 Apr 2022 11:05:37 -0400
Subject: [PATCH 5/8] add constantsOnly test

---
 packages/babel-traverse/src/path/lib/virtual-types.ts |  4 ++--
 packages/babel-traverse/src/scope/index.ts            |  3 ---
 packages/babel-traverse/test/path/isPure.js           | 11 +++++++++++
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/packages/babel-traverse/src/path/lib/virtual-types.ts b/packages/babel-traverse/src/path/lib/virtual-types.ts
index 58505278b3c7..d08fd554eeef 100644
--- a/packages/babel-traverse/src/path/lib/virtual-types.ts
+++ b/packages/babel-traverse/src/path/lib/virtual-types.ts
@@ -124,8 +124,8 @@ export const Generated = {
 };
 
 export const Pure = {
-  checkPath(path: NodePath, opts?): boolean {
-    return path.scope.isPure(path.node, opts);
+  checkPath(path: NodePath, constantsOnly?: boolean): boolean {
+    return path.scope.isPure(path.node, constantsOnly);
   },
 };
 
diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 4d8a60335257..8f76e981452a 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -46,7 +46,6 @@ import {
   isTupleExpression,
   isClassAccessorProperty,
   isObjectProperty,
-  isDecorator,
   isTopicReference,
   isMetaProperty,
 } from "@babel/types";
@@ -864,8 +863,6 @@ export default class Scope {
         if (!this.isPure(prop, constantsOnly)) return false;
       }
       return true;
-    } else if (isDecorator(node)) {
-      return this.isPure(node.expression, constantsOnly);
     } else if (isMethod(node)) {
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
       if (node.decorators?.length > 0) {
diff --git a/packages/babel-traverse/test/path/isPure.js b/packages/babel-traverse/test/path/isPure.js
index 6d32a209618e..62fa0538baf6 100644
--- a/packages/babel-traverse/test/path/isPure.js
+++ b/packages/babel-traverse/test/path/isPure.js
@@ -96,3 +96,14 @@ describe("isPure() returns false", () => {
     },
   );
 });
+
+describe("isPure(constantsOnly: true) returns false", () => {
+  it.each(["x", "1 + x", "({ [x]: 0 })", "(class { static x = x })"])(
+    `NodePath(%p).get("body.0.expression").isPure(/* constantsOnly */true) should be false`,
+    input => {
+      const path = getPath(input).get("body.0.expression");
+      expect(path.node).toBeTruthy();
+      expect(path.isPure(true)).toBe(false);
+    },
+  );
+});

From d9b69e031bdfc4bebbe73d4f971b6aa57662cae6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Wed, 6 Apr 2022 11:11:09 -0400
Subject: [PATCH 6/8] update isPure type definitions

---
 packages/babel-traverse/scripts/generators/validators.js | 2 ++
 packages/babel-traverse/src/path/generated/validators.ts | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/babel-traverse/scripts/generators/validators.js b/packages/babel-traverse/scripts/generators/validators.js
index f806fc76c724..f0e4e239d72c 100644
--- a/packages/babel-traverse/scripts/generators/validators.js
+++ b/packages/babel-traverse/scripts/generators/validators.js
@@ -24,6 +24,8 @@ export interface NodePathValidators {
       output += `is${type}(opts?: object): this is NodePath<t.${type}>;`;
     } else if (types /* in VirtualTypeAliases */) {
       output += `is${type}(opts?: object): this is NodePath<VirtualTypeAliases["${type}"]>;`;
+    } else if (type === "Pure") {
+      output += `isPure(constantsOnly?: boolean): boolean;`;
     } else {
       // if it don't have types, then VirtualTypeAliases[type] is t.Node
       // which TS marked as always true
diff --git a/packages/babel-traverse/src/path/generated/validators.ts b/packages/babel-traverse/src/path/generated/validators.ts
index c552da721622..bc1a246fd319 100644
--- a/packages/babel-traverse/src/path/generated/validators.ts
+++ b/packages/babel-traverse/src/path/generated/validators.ts
@@ -441,7 +441,7 @@ export interface NodePathValidators {
   isNumericLiteralTypeAnnotation(
     opts?: object,
   ): this is NodePath<VirtualTypeAliases["NumericLiteralTypeAnnotation"]>;
-  isPure(opts?: object): boolean;
+  isPure(constantsOnly?: boolean): boolean;
   isReferenced(opts?: object): boolean;
   isReferencedIdentifier(
     opts?: object,

From 18c5ad749c0e5214d281cd32dd289f455be068d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Wed, 6 Apr 2022 13:20:33 -0400
Subject: [PATCH 7/8] remove unreachable codes

---
 packages/babel-traverse/src/scope/index.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 8f76e981452a..9d8a408d51d7 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -44,7 +44,6 @@ import {
   variableDeclarator,
   isRecordExpression,
   isTupleExpression,
-  isClassAccessorProperty,
   isObjectProperty,
   isTopicReference,
   isMetaProperty,
@@ -869,7 +868,7 @@ export default class Scope {
         return false;
       }
       return true;
-    } else if (isProperty(node) || isClassAccessorProperty(node)) {
+    } else if (isProperty(node)) {
       // @ts-expect-error todo(flow->ts): computed in not present on private properties
       if (node.computed && !this.isPure(node.key, constantsOnly)) return false;
       if (node.decorators?.length > 0) {

From 02a010c2a2275839131379da0d04a7dbd495bcec Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Wed, 6 Apr 2022 13:45:00 -0400
Subject: [PATCH 8/8] private-in is pure

---
 packages/babel-traverse/src/scope/index.ts  | 4 +++-
 packages/babel-traverse/test/path/isPure.js | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/babel-traverse/src/scope/index.ts b/packages/babel-traverse/src/scope/index.ts
index 9d8a408d51d7..d6ec6605fbaa 100644
--- a/packages/babel-traverse/src/scope/index.ts
+++ b/packages/babel-traverse/src/scope/index.ts
@@ -47,6 +47,7 @@ import {
   isObjectProperty,
   isTopicReference,
   isMetaProperty,
+  isPrivateName,
 } from "@babel/types";
 import type * as t from "@babel/types";
 import { scope as scopeCache } from "../cache";
@@ -831,7 +832,8 @@ export default class Scope {
     } else if (
       isThisExpression(node) ||
       isMetaProperty(node) ||
-      isTopicReference(node)
+      isTopicReference(node) ||
+      isPrivateName(node)
     ) {
       return true;
     } else if (isClass(node)) {
diff --git a/packages/babel-traverse/test/path/isPure.js b/packages/babel-traverse/test/path/isPure.js
index 62fa0538baf6..70c67f4f6f0c 100644
--- a/packages/babel-traverse/test/path/isPure.js
+++ b/packages/babel-traverse/test/path/isPure.js
@@ -30,6 +30,7 @@ describe("isPure() returns true", () => {
     "class C { #x = f(); static #y }",
     "class C { static target = new.target }",
     "class X { get foo() { return 1 } set foo(v) {} }",
+    "class C { static #p = #p in C }",
   ])(`NodePath(%p).get("body.0").isPure() should be true`, input => {
     const path = getPath(input).get("body.0");
     expect(path.node).toBeTruthy();