report extra comma in if test as an error. fixes #30

jlchmura · Feb 19, 2024 · b385c69 · b385c69
1 parent b46c0a5
commit b385c69
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Showing 2 changed files with 20 additions and 7 deletions.
diff --git a/src/parser/lpcParser.ts b/src/parser/lpcParser.ts
@@ -79,10 +79,11 @@ export interface LPCDocument {
 }
 
 export const enum ParseExpressionFlag {
-  StatementOnly = 0b0000,
+  StatementOnly    = 0b0000,
   AllowDeclaration = 0b0001,
-  AllowFunction = 0b0010,
-  AllowMultiDecl = 0b0100,
+  AllowFunction    = 0b0010,
+  AllowMultiDecl   = 0b0100,
+  NoCommas         = 0b1000,
 }
 
 export class ParserError extends Error {
@@ -424,6 +425,8 @@ export class LPCParser {
     );
     const children: LPCNode[] = [];
 
+    const allowCommaSeparator = !(flags & ParseExpressionFlag.NoCommas);
+
     let t: TokenType,
       lastToken: TokenType = 0;
     // scan until we get a paren block end
@@ -432,7 +435,7 @@ export class LPCParser {
     let possibleImpliedBinary = false;
     while ((t = this.scanner.peek()) && t != endsWith && t != TokenType.EOS) {
       if (
-        t == TokenType.Comma ||
+        (allowCommaSeparator && t == TokenType.Comma) ||
         t == TokenType.BlankLines ||
         t == TokenType.Whitespace
       ) {
@@ -780,7 +783,7 @@ export class LPCParser {
           if (!nd.consequent) {
             nd.test = this.parseParenBlock(
               nd,
-              ParseExpressionFlag.StatementOnly
+              ParseExpressionFlag.StatementOnly | ParseExpressionFlag.NoCommas
             );
             this.eatWhitespaceAndNewlines();
             break;

diff --git a/src/plugin/print/tests/index.spec.ts b/src/plugin/print/tests/index.spec.ts
@@ -1,6 +1,6 @@
 import * as prettier from "prettier";
 import * as prettierPlugin from "../..";
-import { ParseLPC } from "../../../parser/lpcParser";
+import { ParseLPC, ParserError } from "../../../parser/lpcParser";
 import {
   assign_exp_suffix_comment,
   for_loop_various,
@@ -38,6 +38,7 @@ describe("prettier-lpc plugin", () => {
 
     // always validating that the result of formatting is backward compatible with JSONata
     expect(() => ParseLPC(formatted)).not.toThrow();
+
     return formatted;
   };
 
@@ -581,7 +582,7 @@ describe("prettier-lpc plugin", () => {
     formatted = format(`int i=0; test() { indices = ({i, index++}); }`);
     expect(formatted).toMatchSnapshot("assignment_inside_array");
   });
-  
+
   describe("If statements", () => {
     test("formats if statements", () => {
       let formatted = format(if_condense_test);
@@ -592,6 +593,15 @@ describe("prettier-lpc plugin", () => {
       let formatted = format(ifWithExtraCurlyBrackets);
       expect(formatted).toMatchSnapshot("ifWithExtraCurlyBrackets");
     });
+
+    test("Ifs with invalid commas", () => {
+      // this should throw an error because of the comma after present()
+      expect(() =>
+        format(
+          `void test() { if(present("string"), this_object()) { return 1; } }`
+        )
+      ).toThrow(ParserError);
+    });
   });
 
   test("formats for loops", () => {