[bugfix] callable types suggestion forgot parens on unions and inters…

…ections (#3342)
palantir · Oct 18, 2017 · 74d84be · 74d84be
1 parent 349d1b8
commit 74d84be
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Showing 3 changed files with 33 additions and 3 deletions.
diff --git a/src/rules/callableTypesRule.ts b/src/rules/callableTypesRule.ts
@@ -45,8 +45,7 @@ export class Rule extends Lint.Rules.AbstractRule {
 
 function walk(ctx: Lint.WalkContext<void>) {
     return ts.forEachChild(ctx.sourceFile, function cb(node: ts.Node): void {
-        if ((isInterfaceDeclaration(node) && noSupertype(node)
-             || isTypeLiteralNode(node))
+        if ((isInterfaceDeclaration(node) && noSupertype(node) || isTypeLiteralNode(node))
             && node.members.length === 1) {
             const member = node.members[0];
             if (isCallSignatureDeclaration(member) &&
@@ -82,11 +81,15 @@ function noSupertype(node: ts.InterfaceDeclaration): boolean {
 function renderSuggestion(call: ts.CallSignatureDeclaration,
                           parent: ts.InterfaceDeclaration | ts.TypeLiteralNode,
                           sourceFile: ts.SourceFile): string {
+
     const start = call.getStart(sourceFile);
     const colonPos = call.type!.pos - 1 - start;
     const text = sourceFile.text.substring(start, call.end);
-    const suggestion = `${text.substr(0, colonPos)} =>${text.substr(colonPos + 1)}`;
 
+    let suggestion = `${text.substr(0, colonPos)} =>${text.substr(colonPos + 1)}`;
+    if (shouldWrapSuggestion(parent.parent!)) {
+        suggestion = `(${suggestion})`;
+    }
     if (parent.kind === ts.SyntaxKind.InterfaceDeclaration) {
         if (parent.typeParameters !== undefined) {
             return `type${sourceFile.text.substring(parent.name.pos, parent.typeParameters.end + 1)} = ${suggestion}`;
@@ -96,3 +99,13 @@ function renderSuggestion(call: ts.CallSignatureDeclaration,
     }
     return suggestion.endsWith(";") ? suggestion.slice(0, -1) : suggestion;
 }
+
+function shouldWrapSuggestion(parent: ts.Node) {
+    switch (parent.kind) {
+        case ts.SyntaxKind.UnionType:
+        case ts.SyntaxKind.IntersectionType:
+            return true;
+        default:
+            return false;
+    }
+}
diff --git a/test/rules/callable-types/test.ts.fix b/test/rules/callable-types/test.ts.fix
@@ -12,6 +12,11 @@ type U = <T>(t: T) => T
 
 var fn: () => void;
 function f(x: () => void): void;
+function f(x: string | (() => void)): void;
+function f(x: string | (() => void)): void;
+function f(x: (() => string) | (() => number)): void;
+function f(x: string & (() => void)): void;
+function f(x: (() => string) & (() => number)): void;
 
 // Overloads OK
 interface K {

diff --git a/test/rules/callable-types/test.ts.lint b/test/rules/callable-types/test.ts.lint
@@ -32,6 +32,18 @@ var fn: {(): void;};
          ~~~~~~~~~ [type % ('() => void')]
 function f(x: { (): void }): void;
                 ~~~~~~~~ [type % ('() => void')]
+function f(x: string | { (): void }): void;
+                         ~~~~~~~~ [type % ('(() => void)')]
+function f(x: string | ({ (): void })): void;
+                          ~~~~~~~~ [type % ('() => void')]
+function f(x: { (): string } | { (): number }): void;
+                ~~~~~~~~~~ [type % ('(() => string)')]
+                                 ~~~~~~~~~~ [type % ('(() => number)')]
+function f(x: string & { (): void }): void;
+                         ~~~~~~~~ [type % ('(() => void)')]
+function f(x: { (): string } & { (): number }): void;
+                ~~~~~~~~~~ [type % ('(() => string)')]
+                                 ~~~~~~~~~~ [type % ('(() => number)')]
 
 // Overloads OK
 interface K {