Fixed bug with incorrect handle of unary sub operator

Author: KyrylR

src/utils/ExpressionHelper.ts

@@ -248,8 +248,10 @@ class ExpressionVisitor extends ExtendedCircomVisitor<CircomValueType | null> {
         return firstExpression ? 0n : 1n;
       case CircomParser.BNOT:
         return ~firstExpression;
-      case CircomParser.SUB:
-        return -firstExpression;
+    }
+
+    if (operationType == CircomParser.SUB && ctx.expression(1) == null) {
+      return -firstExpression;
     }
 
     const secondExpression = this.visit(ctx.expression(1));

test/circom-template-inputs-visitor.test.ts

@@ -169,4 +169,41 @@ describe("Circom Template Inputs Visitor", () => {
     expect(visitor.templateInputs.out.type).to.equal("output");
     expect(visitor.templateInputs.out.dimension).to.deep.equal([]);
   });
+
+  it("should analyse the BigModNonEqual.circom circuit", () => {
+    const data = getData("BigModNonEqual.circom");
+
+    const visitor = new CircomTemplateInputsVisitor(
+      "BigModNonEqual.circom",
+      data.templates[data.mainComponentInfo.templateName!].context,
+      buildVariableContext(
+        data.templates[data.mainComponentInfo.templateName!].parameters,
+        data.mainComponentInfo.parameters,
+      ),
+    );
+
+    visitor.startParse();
+
+    console.log(visitor.templateInputs);
+
+    expect(visitor.errors.length).to.equal(0);
+
+    expect(visitor.templateInputs.base.type).to.equal("input");
+    expect(visitor.templateInputs.base.dimension).to.deep.equal([6]);
+
+    expect(visitor.templateInputs.modulus.type).to.equal("input");
+    expect(visitor.templateInputs.modulus.dimension).to.deep.equal([4]);
+
+    expect(visitor.templateInputs.dummy.type).to.equal("input");
+    expect(visitor.templateInputs.dummy.dimension).to.deep.equal([]);
+
+    expect(visitor.templateInputs.div.type).to.equal("output");
+    expect(visitor.templateInputs.div.dimension).to.deep.equal([3]);
+
+    expect(visitor.templateInputs.mod.type).to.equal("output");
+    expect(visitor.templateInputs.mod.dimension).to.deep.equal([4]);
+
+    expect(visitor.templateInputs.another.type).to.equal("output");
+    expect(visitor.templateInputs.another.dimension).to.deep.equal([4]);
+  });
 });

test/data/BigModNonEqual.circom

@@ -0,0 +1,17 @@
+pragma circom 2.1.8;
+
+template BigModNonEqual(CHUNK_SIZE, CHUNK_NUMBER_BASE, CHUNK_NUMBER_MODULUS){
+    var CHUNK_NUMBER_DIV = CHUNK_NUMBER_BASE - CHUNK_NUMBER_MODULUS + 1;
+
+    var SOME_RANDOM = -CHUNK_NUMBER_BASE + 10;
+
+    signal input base[CHUNK_NUMBER_BASE];
+    signal input modulus[CHUNK_NUMBER_MODULUS];
+    signal input dummy;
+
+    signal output div[CHUNK_NUMBER_DIV];
+    signal output mod[CHUNK_NUMBER_MODULUS];
+    signal output another[SOME_RANDOM];
+}
+
+component main = BigModNonEqual(64, 6, 4);