feat: optional types for self argument in extends mutates functio…

…ns (#854)

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Optional types for `self` argument in `extends mutates` functions are now allowed: PR [#854](https://github.com/tact-lang/tact/pull/854)
+
 ### Fixed
 
 - Collisions in getter method ids are now handled and reported properly: PR [#875](https://github.com/tact-lang/tact/pull/875)

src/generator/writers/writeExpression.ts

@@ -558,13 +558,6 @@ export function writeExpression(f: AstExpression, wCtx: WriterContext): string {
 
         // Reference type
         if (selfTyRef.kind === "ref") {
-            if (selfTyRef.optional) {
-                throwCompilationError(
-                    `Cannot call function of non - direct type: "${printTypeRef(selfTyRef)}"`,
-                    f.loc,
-                );
-            }
-
             // Render function call
             const selfTy = getType(wCtx.ctx, selfTyRef.name);
 

src/generator/writers/writeFunction.ts

@@ -503,7 +503,7 @@ function writeCondition(
 
 export function writeFunction(f: FunctionDescription, ctx: WriterContext) {
     // Resolve self
-    const self = f.self ? getType(ctx.ctx, f.self) : null;
+    const self = f.self?.kind === "ref" ? getType(ctx.ctx, f.self.name) : null;
 
     // Write function header
     let returns: string = resolveFuncType(f.returns, ctx);
@@ -683,7 +683,7 @@ function writeNonMutatingFunction(
 
 export function writeGetter(f: FunctionDescription, ctx: WriterContext) {
     // Render tensors
-    const self = f.self !== null ? getType(ctx.ctx, f.self) : null;
+    const self = f.self?.kind === "ref" ? getType(ctx.ctx, f.self.name) : null;
     if (!self) {
         throw new Error(`No self type for getter ${idTextErr(f.name)}`); // Impossible
     }

src/storage/__snapshots__/resolveAllocation.spec.ts.snap

@@ -2293,7 +2293,11 @@ exports[`resolveAllocation should write program 1`] = `
           "returns": {
             "kind": "void",
           },
-          "self": "Sample",
+          "self": {
+            "kind": "ref",
+            "name": "Sample",
+            "optional": false,
+          },
         },
       },
       "header": null,

src/test/e2e-emulated/contracts/mutating-method-chaining.tact → src/test/e2e-emulated/contracts/mutating-methods.tact

@@ -1,8 +1,17 @@
+asm(value key self keySize) extends mutates fun nativeUdictStoreUint(self: Cell?, keySize: Int, key: Int, value: Slice) { DICTUSET }
+
 extends mutates fun multiply(self: Int, x: Int): Int {
     self *= x;
     return self;
 }
 
+extends fun multiplyExtends(self: Int?, x: Int): Int? {
+    if (self == null) {
+        return null;
+    }
+    return self!! * x;
+}
+
 struct Foo {
     s: Slice;
 }
@@ -64,4 +73,15 @@ contract Tester {
         self.s.loadUint(1);
         return self.s.loadUint(3);
     }
+
+    get fun test10(dict: Cell?): Cell? {
+        dict.nativeUdictStoreUint(8, 123, rawSlice("456"));
+        return dict;
+    }
+
+    get fun test11(x: Int?): Int? {
+        x.multiplyExtends(2);
+        x.multiplyExtends(2).multiplyExtends(3);
+        return x.multiplyExtends(2).multiplyExtends(3);
+    }
 }

src/test/e2e-emulated/mutating-method-chaining.spec.ts → src/test/e2e-emulated/mutating-methods.spec.ts

@@ -1,6 +1,6 @@
-import { toNano } from "@ton/core";
+import { beginCell, BitString, Dictionary, toNano } from "@ton/core";
 import { Blockchain, SandboxContract, TreasuryContract } from "@ton/sandbox";
-import { Tester } from "./contracts/output/mutating-method-chaining_Tester";
+import { Tester } from "./contracts/output/mutating-methods_Tester";
 import "@ton/test-utils";
 
 describe("bugs", () => {
@@ -52,5 +52,41 @@ describe("bugs", () => {
         expect(await contract.getTest7()).toBe(42n);
         expect(await contract.getTest8()).toBe(5n);
         expect(await contract.getTest9()).toBe(5n);
+
+        // Test `extends mutates` function with optional self param
+        {
+            // Non-empty dictionary
+            const d = Dictionary.empty(
+                Dictionary.Keys.Uint(8),
+                Dictionary.Values.BitString(12),
+            );
+            d.set(1, new BitString(Buffer.from("1234", "hex"), 0, 12));
+            const c = beginCell().storeDictDirect(d).endCell();
+            const c2 = await contract.getTest10(c);
+            const d2 = c2
+                ?.beginParse()
+                .loadDictDirect(
+                    Dictionary.Keys.Uint(8),
+                    Dictionary.Values.BitString(12),
+                );
+            expect(d2?.size).toBe(2);
+            expect(d2?.get(1)?.toString()).toBe("123");
+            expect(d2?.get(123)?.toString()).toBe("456");
+        }
+        {
+            // Empty dictionary
+            const c = await contract.getTest10(null);
+            const d = c
+                ?.beginParse()
+                .loadDictDirect(
+                    Dictionary.Keys.Uint(8),
+                    Dictionary.Values.BitString(12),
+                );
+            expect(d?.size).toBe(1);
+            expect(d?.get(123)?.toString()).toBe("456");
+        }
+
+        expect(await contract.getTest11(1n)).toBe(6n);
+        expect(await contract.getTest11(2n)).toBe(12n);
     });
 });