fix: Prohibited empty inherited trait lists

See: #247

CHANGELOG.md

@@ -19,7 +19,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Update the `dump` function to handle addresses: PR [#175](https://github.com/tact-lang/tact/pull/175)
-- Support trailing commas in all comma-separated lists (struct instance fields, `initOf` arguments, `init()` parameters, inherited traits via `with`, function arguments and parameters): PR [#179](https://github.com/tact-lang/tact/pull/179) and PR [#246](https://github.com/tact-lang/tact/pull/246)
+- Support trailing commas in all comma-separated lists (struct instantiations, `initOf` arguments, `init()` parameters, inherited traits via `with`, function arguments and parameters): PR [#179](https://github.com/tact-lang/tact/pull/179) and PR [#246](https://github.com/tact-lang/tact/pull/246)
 - The implicit empty `init` function is now present by default in the contract if not declared: PR [#167](https://github.com/tact-lang/tact/pull/167)
 - `@stdlib/stoppable` now imports `@stdlib/ownable` so the programmer does not have to do it separately: PR [#193](https://github.com/tact-lang/tact/pull/193)
 - Support escape sequences for strings (`\\`, `\"`, `\n`, `\r`, `\t`, `\v`, `\b`, `\f`, `\u{0}` through `\u{FFFFFF}`, `\u0000` through `\uFFFF`, `\x00` through `\xFF`): PR [#192](https://github.com/tact-lang/tact/pull/192)
@@ -28,6 +28,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Incorrect "already exists" errors when using names such as `toString` or `valueOf`: PR [#208](https://github.com/tact-lang/tact/pull/208)
 - Escape backticks in error messages for generated TypeScript code: PR [#192](https://github.com/tact-lang/tact/pull/192)
+- Empty inherited trait lists after `with` keyword are now disallowed: PR [#246](https://github.com/tact-lang/tact/pull/246)
 
 ## [1.2.0] - 2024-02-29
 

src/grammar/__snapshots__/grammar.spec.ts.snap

@@ -255,7 +255,7 @@ Line 2, col 31:
 `;
 
 exports[`grammar should fail case-27 1`] = `
-"<unknown>:1:19: Empty inherited traits list should not have a dangling comma.
+"<unknown>:1:19: Syntax error: expected "_", "A".."Z", or "a".."z" 
 Line 1, col 19:
 > 1 | contract Name with, {}
                         ^
@@ -264,7 +264,7 @@ Line 1, col 19:
 `;
 
 exports[`grammar should fail case-28 1`] = `
-"<unknown>:1:16: Empty inherited traits list should not have a dangling comma.
+"<unknown>:1:16: Syntax error: expected "_", "A".."Z", or "a".."z" 
 Line 1, col 16:
 > 1 | trait Name with, {}
                      ^
@@ -282,6 +282,24 @@ Line 2, col 10:
 "
 `;
 
+exports[`grammar should fail case-30 1`] = `
+"<unknown>:1:20: Syntax error: expected "_", "A".."Z", or "a".."z" 
+Line 1, col 20:
+> 1 | contract Name with {}
+                         ^
+  2 | 
+"
+`;
+
+exports[`grammar should fail case-31 1`] = `
+"<unknown>:1:17: Syntax error: expected "_", "A".."Z", or "a".."z" 
+Line 1, col 17:
+> 1 | trait Name with {}
+                      ^
+  2 | 
+"
+`;
+
 exports[`grammar should parse case-0 1`] = `
 {
   "entries": [

src/grammar/grammar.ohm

@@ -45,7 +45,7 @@ Tact {
 
     // Contract
     Contract = ContractAttribute* contract id "{" ContractBody* "}" --simple
-             | ContractAttribute* contract id with ListOf<id,","> ","? "{" ContractBody* "}" --withTraits
+             | ContractAttribute* contract id with NonemptyListOf<id,","> ","? "{" ContractBody* "}" --withTraits
     ContractInit = "init" "(" ListOf<FunctionArg,","> ","? ")" "{" Statement* "}"
     ContractBody = Field
                  | ContractInit
@@ -55,7 +55,7 @@ Tact {
 
     // Trait
     Trait = ContractAttribute* trait id "{" TraitBody* "}" --originary
-          | ContractAttribute* trait id with ListOf<id,","> ","? "{" TraitBody* "}" --withTraits
+          | ContractAttribute* trait id with NonemptyListOf<id,","> ","? "{" TraitBody* "}" --withTraits
     TraitBody = Field
               | ReceiveFunction
               | Function

src/grammar/grammar.ts

@@ -113,18 +113,11 @@ semantics.addOperation<ASTNode>("resolve_program_item", {
         arg2,
         _arg3,
         arg4,
-        arg5,
+        _arg5,
         _arg6,
         arg7,
         _arg8,
     ) {
-        if (arg4.source.contents === "" && arg5.sourceString === ",") {
-            throwError(
-                "Empty inherited traits list should not have a dangling comma.",
-                createRef(arg5),
-            );
-        }
-
         checkVariableName(arg2.sourceString, createRef(arg2));
         return createNode({
             kind: "def_contract",
@@ -154,14 +147,17 @@ semantics.addOperation<ASTNode>("resolve_program_item", {
             ref: createRef(this),
         });
     },
-    Trait_withTraits(arg0, _arg1, arg2, _arg3, arg4, arg5, _arg6, arg7, _arg8) {
-        if (arg4.source.contents === "" && arg5.sourceString === ",") {
-            throwError(
-                "Empty inherited traits list should not have a dangling comma.",
-                createRef(arg5),
-            );
-        }
-
+    Trait_withTraits(
+        arg0,
+        _arg1,
+        arg2,
+        _arg3,
+        arg4,
+        _arg5,
+        _arg6,
+        arg7,
+        _arg8,
+    ) {
         checkVariableName(arg2.sourceString, createRef(arg2));
         return createNode({
             kind: "def_trait",

src/grammar/test-failed/case-30.tact

@@ -0,0 +1 @@
+contract Name with {}

src/grammar/test-failed/case-31.tact

@@ -0,0 +1 @@
+trait Name with {}