JavaScript: Fix pipeline bugs (#7979)

* Fix arrow regression

* Fix resolvePluginConflict

* Update changelog

* Fix condition

* Edit changelog: add link to Babel blog, change order (to be as in the blog)

Co-authored-by: Georgii Dolzhykov <thorn.mailbox@gmail.com>

changelog_unreleased/javascript/pr-6319.md

@@ -1,36 +1,37 @@
-#### Support the 'smart' and 'fsharp-style' pipeline operator proposal ([#6319](https://github.com/prettier/prettier/pull/6319) by [@sosukesuzuki](https://github.com/sosukesuzuki), [@thorn0](https://github.com/thorn0))
+#### Support the F# and Smart pipeline operator proposals ([#6319](https://github.com/prettier/prettier/pull/6319) by [@sosukesuzuki](https://github.com/sosukesuzuki), [@thorn0](https://github.com/thorn0), [#7979](https://github.com/prettier/prettier/pull/7979) by [@sosukesuzuki](https://github.com/sosukesuzuki))
 
-- [Link to the 'smart' pipeline proposal](https://github.com/js-choi/proposal-smart-pipelines)
-- [Link to the 'fsharp-style' pipeline proposal](https://github.com/valtech-nyc/proposal-fsharp-pipelines)
+- [F# Pipeline Operator proposal](https://github.com/valtech-nyc/proposal-fsharp-pipelines)
+- [Smart Pipelines proposal](https://github.com/js-choi/proposal-smart-pipelines)
+- [Babel Blog: What's Happening With the Pipeline (`|>`) Proposal?](https://babeljs.io/blog/2018/07/19/whats-happening-with-the-pipeline-proposal)
 
-**Smart Pipeline:**
+**F#-style Pipeline:**
 
 <!-- prettier-ignore -->
 ```js
 // Input
-5 |> # * 2
+promises |> await;
 
-// Output (Prettier Stable)
-SyntaxError: Unexpected character '#' (1:6)
-> 1 | 5 |> # * 2
-    |      ^
+// Output (Prettier stable)
+SyntaxError: Unexpected token (1:18)
+> 1 | promises |> await;
+    |                  ^
 
 // Output (Prettier master)
-5 |> # * 2
+promises |> await;
 ```
 
-**F#-style Pipeline:**
+**Smart Pipeline:**
 
 <!-- prettier-ignore -->
 ```js
 // Input
-promises |> await;
+5 |> # * 2
 
-// Output (Prettier stable)
-SyntaxError: Unexpected token (1:18)
-> 1 | promises |> await;
-    |                  ^
+// Output (Prettier Stable)
+SyntaxError: Unexpected character '#' (1:6)
+> 1 | 5 |> # * 2
+    |      ^
 
 // Output (Prettier master)
-promises |> await;
+5 |> # * 2
 ```

src/language-js/needs-parens.js

@@ -583,16 +583,9 @@ function needsParens(path, options) {
           return !!(node.extra && node.extra.parenthesized);
 
         case "BinaryExpression":
-          if (node.extra && node.extra.parenthesized) {
-            return (
-              parent.operator === "|>" ||
-              (parent.operator !== "|>" &&
-                node.body.type === "BinaryExpression" &&
-                node.body.operator === "|>")
-            );
-          }
-          return false;
-
+          return (
+            parent.operator !== "|>" || (node.extra && node.extra.parenthesized)
+          );
         case "NewExpression":
         case "CallExpression":
         case "OptionalCallExpression":

src/language-js/parser-babel.js

@@ -48,12 +48,13 @@ function resolvePluginsConflict(
   pluginCombinations,
   conflictPlugins
 ) {
-  const combinations = [...pluginCombinations];
-  if (condition) {
-    for (const combination of pluginCombinations) {
-      for (const plugin of conflictPlugins) {
-        combinations.push([...combination, plugin]);
-      }
+  if (!condition) {
+    return pluginCombinations;
+  }
+  const combinations = [];
+  for (const combination of pluginCombinations) {
+    for (const plugin of conflictPlugins) {
+      combinations.push([...combination, plugin]);
     }
   }
   return combinations;

tests/binary-expressions/__snapshots__/jsfmt.spec.js.snap

@@ -20,6 +20,9 @@ function f() {
   )
 }
 
+((x) => x) + '';
+'' + ((x) => x);
+
 =====================================output=====================================
 function f() {
   const appEntities = getAppEntities(loadObject).filter(
@@ -43,6 +46,9 @@ function f() {
   );
 }
 
+((x) => x) + "";
+"" + ((x) => x);
+
 ================================================================================
 `;
 

tests/binary-expressions/arrow.js

@@ -11,3 +11,6 @@ function f() {
     }
   )
 }
+
+((x) => x) + '';
+'' + ((x) => x);