fix: account for different scopes during path evaluation

babel · May 3, 2018 · b7f2d70 · b7f2d70
1 parent 663ebc3
commit b7f2d70
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Showing 5 changed files with 32 additions and 16 deletions.
diff --git a/packages/babel-helper-evaluate-path/src/index.js b/packages/babel-helper-evaluate-path/src/index.js
@@ -1,14 +1,14 @@
 "use strict";
 
 module.exports = function evaluate(path, { tdz = false } = {}) {
-  if (!tdz) {
-    return baseEvaluate(path);
-  }
-
   if (path.isReferencedIdentifier()) {
     return evaluateIdentifier(path);
   }
 
+  if (!tdz) {
+    return baseEvaluate(path);
+  }
+
   const state = {
     confident: true
   };
@@ -113,8 +113,12 @@ function evaluateBasedOnControlFlow(binding, refPath) {
       return { shouldDeopt: true };
     }
 
-    let blockParent = binding.path.scope.getBlockParent().path;
     const fnParent = binding.path.getFunctionParent();
+    if (!fnParent) {
+      return { shouldDeopt: true };
+    }
+
+    let blockParent = binding.path.scope.getBlockParent().path;
 
     if (blockParent === fnParent) {
       if (!fnParent.isProgram()) blockParent = blockParent.get("body");

diff --git a/packages/babel-plugin-minify-dead-code-elimination/src/index.js b/packages/babel-plugin-minify-dead-code-elimination/src/index.js
@@ -976,10 +976,14 @@ module.exports = ({ types: t, traverse }) => {
     } else {
       path.traverse({
         VariableDeclaration(varPath) {
-          if (!varPath.isVariableDeclaration({ kind: "var" })) return;
+          const { node } = varPath;
+
+          if (node.kind !== "var") {
+            return;
+          }
           if (!isSameFunctionScope(varPath, path)) return;
 
-          for (const decl of varPath.node.declarations) {
+          for (const decl of node.declarations) {
             const bindingIds = Object.keys(t.getBindingIdentifiers(decl.id));
             declarators.push(
               ...bindingIds.map(name =>

diff --git a/packages/babel-plugin-minify-guarded-expressions/src/index.js b/packages/babel-plugin-minify-guarded-expressions/src/index.js
@@ -1,4 +1,10 @@
 "use strict";
+const evaluate = require("babel-helper-evaluate-path");
+
+function evaluateTruthy(path) {
+  const res = evaluate(path);
+  if (res.confident) return !!res.value;
+}
 
 module.exports = function({ types: t }) {
   const flipExpressions = require("babel-helper-flip-expressions")(t);
@@ -28,28 +34,28 @@ module.exports = function({ types: t }) {
             const shouldBail = !path.parentPath.isExpressionStatement();
 
             if (node.operator === "&&") {
-              const leftTruthy = left.evaluateTruthy();
+              const leftTruthy = evaluateTruthy(left);
               if (leftTruthy === false) {
                 // Short-circuit
                 path.replaceWith(node.left);
               } else if (leftTruthy === true && left.isPure()) {
                 path.replaceWith(node.right);
               } else if (
-                right.evaluateTruthy() === false &&
+                evaluateTruthy(right) === false &&
                 right.isPure() &&
                 !shouldBail
               ) {
                 path.replaceWith(node.left);
               }
             } else if (node.operator === "||") {
-              const leftTruthy = left.evaluateTruthy();
+              const leftTruthy = evaluateTruthy(left);
               if (leftTruthy === false && left.isPure()) {
                 path.replaceWith(node.right);
               } else if (leftTruthy === true) {
                 // Short-circuit
                 path.replaceWith(node.left);
               } else if (
-                right.evaluateTruthy() === false &&
+                evaluateTruthy(right) === false &&
                 right.isPure() &&
                 !shouldBail
               ) {

diff --git a/packages/babel-plugin-minify-simplify/src/helpers.js b/packages/babel-plugin-minify-simplify/src/helpers.js
@@ -1,6 +1,7 @@
 "use strict";
 
 const VOID_0 = t => t.unaryExpression("void", t.numericLiteral(0), true);
+const evaluate = require("babel-helper-evaluate-path");
 
 // Types as Symbols - for comparing types
 const types = {};
@@ -39,7 +40,7 @@ const isPatternMatchesPath = t =>
       return patternValue(inputPath);
     }
     if (isNodeOfType(t, inputPath.node, patternValue)) return true;
-    const evalResult = inputPath.evaluate();
+    const evalResult = evaluate(inputPath);
     if (!evalResult.confident || !inputPath.isPure()) return false;
     return evalResult.value === patternValue;
   };

diff --git a/packages/babel-plugin-minify-simplify/src/logical-expression.js b/packages/babel-plugin-minify-simplify/src/logical-expression.js
@@ -2,13 +2,14 @@
 
 const h = require("./helpers");
 const PatternMatch = require("./pattern-match");
+const evaluate = require("babel-helper-evaluate-path");
 
 module.exports = t => {
   const OP_AND = input => input === "&&";
   const OP_OR = input => input === "||";
 
   function simplifyPatterns(path) {
-    // cache of path.evaluate()
+    // cache of evaluate(path)
     const evaluateMemo = new Map();
 
     const TRUTHY = input => {
@@ -22,7 +23,7 @@ module.exports = t => {
           return true;
         }
       }
-      const evalResult = input.evaluate();
+      const evalResult = evaluate(input);
       evaluateMemo.set(input, evalResult);
       return evalResult.confident && input.isPure() && evalResult.value;
     };
@@ -35,7 +36,7 @@ module.exports = t => {
           return true;
         }
       }
-      const evalResult = input.evaluate();
+      const evalResult = evaluate(input);
       evaluateMemo.set(input, evalResult);
       return evalResult.confident && input.isPure() && !evalResult.value;
     };
@@ -67,7 +68,7 @@ module.exports = t => {
       if (evaluateMemo.has(left)) {
         value = evaluateMemo.get(left).value;
       } else {
-        value = left.evaluate().value;
+        value = evaluate(left).value;
       }
       path.replaceWith(result.value(t.valueToNode(value), right.node));
     }