update spaceWithinParensRule to always allow empty parens (palantir#3513

)

src/rules/spaceWithinParensRule.ts

@@ -28,7 +28,7 @@ export class Rule extends Lint.Rules.AbstractRule {
     /* tslint:disable:object-literal-sort-keys */
     public static metadata: Lint.IRuleMetadata = {
         ruleName: "space-within-parens",
-        description: "Enforces spaces within parentheses or disallow them.",
+        description: "Enforces spaces within parentheses or disallow them.  Empty parentheses () are always allowed.",
         hasFix: true,
         optionsDescription: Lint.Utils.dedent`
             You may enforce the amount of whitespace within parentheses.
@@ -73,9 +73,13 @@ class SpaceWithinParensWalker extends Lint.AbstractWalker<Options> {
     public walk(sourceFile: ts.SourceFile) {
         forEachToken(sourceFile, (token: ts.Node) => {
             if (token.kind === ts.SyntaxKind.OpenParenToken) {
-                this.checkOpenParenToken(token);
+                if (sourceFile.text.charAt(token.end) !== ")") {
+                    this.checkOpenParenToken(token);
+                }
             } else if (token.kind === ts.SyntaxKind.CloseParenToken) {
-                this.checkCloseParenToken(token);
+                if (sourceFile.text.charAt(token.end - 2) !== "(") {
+                    this.checkCloseParenToken(token);
+                }
             }
         });
     }

test/rules/space-within-parens/force-one-space/test.ts.fix

@@ -6,3 +6,6 @@ export function rgb2lab( r : number, g : number, b : number ) : { L : number; a
 
 foo( /*no param*/ );
 
+// empty parens are always allowed
+foo();
+

test/rules/space-within-parens/force-one-space/test.ts.lint

@@ -14,5 +14,8 @@ foo(/*no param*/);
     ~nil [0]
                 ~nil [0]
 
+// empty parens are always allowed
+foo();
+
 [0]: Needs 1 whitespace within parentheses
 [1]: No more than 1 whitespace within parentheses allowed

test/rules/space-within-parens/force-two-spaces/test.ts.fix

@@ -17,6 +17,12 @@ if (  x === y  ) {
     return (  {result: true, error: (  x + y  )}  );
 }
 
-// be well
+// expected number of spaces provided
+new Foo(  );
+
+// empty parens are always allowed
+new Foo();
+
+// Missing a space
 new Foo(  );
 

test/rules/space-within-parens/force-two-spaces/test.ts.lint

@@ -27,9 +27,15 @@ if (x === y) {
                                               ~ [2]
 }
 
-// be well
+// expected number of spaces provided
+new Foo(  );
+
+// empty parens are always allowed
 new Foo();
-        ~nil [1]
+
+// Missing a space
+new Foo( );
+         ~nil [0]
 
 [0]: Needs 1 whitespace within parentheses
 [1]: Needs 2 whitespaces within parentheses

test/rules/space-within-parens/no-space/test.ts.fix

@@ -32,3 +32,6 @@ switch (typeof x) {
         break;
 }
 
+// empty parens are always allowed
+foo();
+

test/rules/space-within-parens/no-space/test.ts.lint

@@ -44,4 +44,7 @@ switch (  typeof x ) {
         break;
 }
 
+// empty parens are always allowed
+foo();
+
 [0]: Whitespace within parentheses is not allowed