Fix formatting error on member chain (#15915)

prettier · Jan 12, 2024 · 7e862bb · 7e862bb
1 parent 12f91dd
commit 7e862bb
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diff --git a/changelog_unreleased/javascript/15915.md b/changelog_unreleased/javascript/15915.md
@@ -0,0 +1,14 @@
+#### Fix formatting error on member chain (#15915 by @sosukesuzuki)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+test().test2().test2(thing?.something);
+
+// Prettier stable
+TypeError: Cannot read properties of undefined (reading 'type')
+
+// Prettier main
+test().test2().test2(thing?.something);
+
+```
diff --git a/src/language-js/utils/index.js b/src/language-js/utils/index.js
@@ -405,6 +405,16 @@ function isTestCall(node, parent) {
 /** @return {(node: Node) => boolean} */
 const skipChainExpression = (fn) => (node) => {
   if (node?.type === "ChainExpression") {
+    // @ts-expect-error
+    if (!node.object) {
+      // @ts-expect-error
+      node.object = node.expression.object;
+    }
+    // @ts-expect-error
+    if (!node.property) {
+      // @ts-expect-error
+      node.property = node.expression.property;
+    }
     node = node.expression;
   }
 

diff --git a/tests/format/js/chain-expression/__snapshots__/jsfmt.spec.js.snap b/tests/format/js/chain-expression/__snapshots__/jsfmt.spec.js.snap
@@ -81,6 +81,22 @@ logger.log(
 ================================================================================
 `;
 
+exports[`issue-15912.js format 1`] = `
+====================================options=====================================
+parsers: ["babel", "typescript", "flow"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+test()
+  .test2()
+  .test2(thing?.something);
+
+=====================================output=====================================
+test().test2().test2(thing?.something);
+
+================================================================================
+`;
+
 exports[`test.js format 1`] = `
 ====================================options=====================================
 parsers: ["babel", "typescript", "flow"]

diff --git a/tests/format/js/chain-expression/issue-15912.js b/tests/format/js/chain-expression/issue-15912.js
@@ -0,0 +1,3 @@
+test()
+  .test2()
+  .test2(thing?.something);