fix: Don't throw in getTypeAnnotation when using TS+inference (#15383)

babel · Jan 15, 2024 · 1200542 · 1200542
1 parent 98c0885
commit 1200542
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Showing 3 changed files with 13 additions and 7 deletions.
diff --git a/packages/babel-traverse/src/path/inference/inferer-reference.ts b/packages/babel-traverse/src/path/inference/inferer-reference.ts
@@ -155,7 +155,6 @@ function inferAnnotationFromBinaryExpression(
 
   if (operator !== "===" && operator !== "==") return;
 
-  //
   let typeofPath: NodePath<t.UnaryExpression>;
   let typePath: NodePath<t.Expression>;
   if (left.isUnaryExpression({ operator: "typeof" })) {

diff --git a/packages/babel-traverse/src/path/inference/util.ts b/packages/babel-traverse/src/path/inference/util.ts
@@ -8,23 +8,23 @@ import {
 import type * as t from "@babel/types";
 
 export function createUnionType(
-  types: Array<t.FlowType | t.TSType>,
-): t.FlowType | t.TSType {
+  types: (t.FlowType | t.TSType)[],
+): t.FlowType | t.TSType | undefined {
   if (process.env.BABEL_8_BREAKING) {
-    if (isFlowType(types[0])) {
+    if (types.every(v => isFlowType(v))) {
       return createFlowUnionType(types as t.FlowType[]);
     }
-    if (isTSType(types[0])) {
+    if (types.every(v => isTSType(v))) {
       return createTSUnionType(types as t.TSType[]);
     }
   } else {
-    if (isFlowType(types[0])) {
+    if (types.every(v => isFlowType(v))) {
       if (createFlowUnionType) {
         return createFlowUnionType(types as t.FlowType[]);
       }
 
       return createUnionTypeAnnotation(types as t.FlowType[]);
-    } else {
+    } else if (types.every(v => isTSType(v))) {
       if (createTSUnionType) {
         return createTSUnionType(types as t.TSType[]);
       }

diff --git a/packages/babel-traverse/test/inference.js b/packages/babel-traverse/test/inference.js
@@ -701,5 +701,12 @@ describe("inference with TypeScript", function () {
       const path = tsGetPath(input).get("body.0.expression");
       expect(path.isGenericType("Array")).toBe(true);
     });
+    it("should not throw both flow and ts types", () => {
+      const path = tsGetPath(
+        `const bar = 0 ? mkList() : [];function mkList(): any[] {return [];}`,
+      ).get("body.0.declarations.0");
+      // TODO: This should be true
+      expect(path.isGenericType("Array")).toBe(false);
+    });
   });
 });