Flow: Improve comment types detection (#9563)

changelog_unreleased/flow/pr-9563.md

@@ -0,0 +1,22 @@
+#### Improve comment types detection (#9563 by @fisker)
+
+<!-- prettier-ignore -->
+```jsx
+// Input
+foo/*::<bar>*/(baz);
+class Foo {
+  bar( data: Array<string>) {}
+}
+
+// Prettier master
+foo/*:: <bar> */(baz);
+class Foo {
+  bar(data: Array/*:: <string> */) {}
+}
+
+// Prettier stable
+foo/*:: <bar> */(baz);
+class Foo {
+  bar(data: Array<string>) {}
+}
+```

src/language-js/printer-estree.js

@@ -2899,21 +2899,25 @@ function printPathNoParens(path, options, print, args) {
 
     case "TypeParameterDeclaration":
     case "TypeParameterInstantiation": {
-      const value = path.getValue();
-      const commentStart = options.originalText
-        .slice(0, locStart(value))
-        .lastIndexOf("/*");
-      // As noted in the TypeCastExpression comments above, we're able to use a normal whitespace regex here
-      // because we know for sure that this is a type definition.
-      const commentSyntax =
-        commentStart >= 0 &&
-        options.originalText.slice(commentStart).match(/^\/\*\s*::/);
-      if (commentSyntax) {
-        return concat([
-          "/*:: ",
-          printTypeParameters(path, options, print, "params"),
-          " */",
-        ]);
+      const start = locStart(n);
+      const end = locEnd(n);
+      const commentStartIndex = options.originalText.lastIndexOf("/*", start);
+      const commentEndIndex = options.originalText.indexOf("*/", end);
+      if (commentStartIndex !== -1 && commentEndIndex !== -1) {
+        const comment = options.originalText
+          .slice(commentStartIndex + 2, commentEndIndex)
+          .trim();
+        if (
+          comment.startsWith("::") &&
+          !comment.includes("/*") &&
+          !comment.includes("*/")
+        ) {
+          return concat([
+            "/*:: ",
+            printTypeParameters(path, options, print, "params"),
+            " */",
+          ]);
+        }
       }
 
       return printTypeParameters(path, options, print, "params");

tests/flow/comments/__snapshots__/jsfmt.spec.js.snap

@@ -293,6 +293,25 @@ const x = (input /*: string */) /*: string */ => {};
 ================================================================================
 `;
 
+exports[`type_annotations-2.js format 1`] = `
+====================================options=====================================
+parsers: ["flow", "babel"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+foo/*::<bar>*/(baz);
+class Foo {
+  bar( data: Array<string>) {}
+}
+=====================================output=====================================
+foo/*:: <bar> */(baz);
+class Foo {
+  bar(data: Array<string>) {}
+}
+
+================================================================================
+`;
+
 exports[`union.js format 1`] = `
 ====================================options=====================================
 parsers: ["flow", "babel"]

tests/flow/comments/babel-only/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,30 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`type_annotations-3.js format 1`] = `
+====================================options=====================================
+parsers: ["babel-flow"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+import type { OneType } from './oneFile.js'
+/*::
+import type { HelloType } from './otherFile.js'
+*/
+
+type PropTypes = {|
+  TestComponent: React.AbstractComponent<any>,
+  hello: HelloType,
+|};
+=====================================output=====================================
+import type { OneType } from "./oneFile.js";
+/*::
+import type { HelloType } from './otherFile.js'
+*/
+
+type PropTypes = {|
+  TestComponent: React.AbstractComponent<any>,
+  hello: HelloType,
+|};
+
+================================================================================
+`;

tests/flow/comments/babel-only/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, ["babel-flow"]);

tests/flow/comments/babel-only/type_annotations-3.js

@@ -0,0 +1,9 @@
+import type { OneType } from './oneFile.js'
+/*::
+import type { HelloType } from './otherFile.js'
+*/
+
+type PropTypes = {|
+  TestComponent: React.AbstractComponent<any>,
+  hello: HelloType,
+|};

tests/flow/comments/type_annotations-2.js

@@ -0,0 +1,4 @@
+foo/*::<bar>*/(baz);
+class Foo {
+  bar( data: Array<string>) {}
+}