Added support for legacy ABI JSON fragments (ethers-io#3932).

Author: ricmoo

src.ts/_tests/test-abi.ts

@@ -136,3 +136,142 @@ describe("Test Interface", function() {
         assert.equal(log.args[2], BigInt(234));
     });
 });
+
+describe("Tests Legacy ABI formats", function() {
+
+    // See: #3932
+    const iface = new Interface([
+        {
+            name: "implicitView",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "constant": true,
+            "payable": false,
+            "type": "function"
+        },
+        {
+            name: "implicitSendNonpay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "constant": false,
+            "payable": false,
+            "type": "function"
+        },
+        {
+            name: "implicitSendPay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "constant": false,
+            "payable": true,
+            "type": "function"
+        },
+        {
+            name: "implicitSendImplicitPay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "constant": false,
+            "type": "function"
+        },
+        {
+            name: "implicitSendExplicitPay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            payable: true,
+            type: "function"
+        },
+        {
+            name: "implicitSendExplicitNonpay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            payable: false,
+            type: "function"
+        },
+        {
+            name: "implicitAll",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "type": "function"
+        },
+        {
+            name: "explicitView",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "stateMutability": "view",
+            "constant": true,
+            "payable": false,
+            "type": "function"
+        },
+        {
+            name: "explicitPure",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "stateMutability": "pure",
+            "constant": true,
+            "payable": false,
+            "type": "function"
+        },
+        {
+            name: "explicitPay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "stateMutability": "payable",
+            "constant": true,
+            "payable": true,
+            "type": "function"
+        },
+        {
+            name: "explicitNonpay",
+            outputs: [ ],
+            inputs: [
+                { type: "int128", name: "arg0" }
+            ],
+            "stateMutability": "nonpayable",
+            "constant": true,
+            "payable": false,
+            "type": "function"
+        },
+    ]);
+
+    function test(name: string, isConst: boolean, payable: boolean, stateMutability: string): void {
+        it(`tests ABI configuration: ${ name }`, function() {
+            const f = iface.getFunction(name);
+            assert.ok(!!f, `missing ${ name }`);
+            assert.equal(f.constant, isConst, `${ name }.constant`);
+            assert.equal(f.stateMutability, stateMutability, `${ name }.stateMutability`);
+            assert.equal(f.payable, payable, `${ name }.payable`);
+        });
+    }
+
+    test("explicitView", true, false, "view");
+    test("explicitPure", true, false, "pure");
+    test("explicitPay", false, true, "payable");
+    test("explicitNonpay", false, false, "nonpayable");
+
+    test("implicitView", true, false, "view");
+    test("implicitSendNonpay", false, false, "nonpayable");
+    test("implicitSendPay", false, true, "payable");
+    test("implicitSendImplicitPay", false, true, "payable");
+    test("implicitSendExplicitPay", false, true, "payable");
+    test("implicitSendExplicitNonpay", false, false, "nonpayable");
+    test("implicitAll", false, true, "payable");
+});

src.ts/abi/fragments.ts

@@ -1430,9 +1430,29 @@ export class FunctionFragment extends NamedFragment {
             return new FunctionFragment(_guard, name, mutability, inputs, outputs, gas);
         }
 
-        // @TODO: verifyState for stateMutability
+        let stateMutability = obj.stateMutability;
+
+        // Use legacy Solidity ABI logic if stateMutability is missing
+        if (stateMutability == null) {
+            stateMutability = "payable";
+
+            if (typeof(obj.constant) === "boolean") {
+                stateMutability = "view";
+                if (!obj.constant) {
+                    stateMutability = "payable"
+                    if (typeof(obj.payable) === "boolean" && !obj.payable) {
+                        stateMutability = "nonpayable";
+                    }
+                }
+            } else if (typeof(obj.payable) === "boolean" && !obj.payable) {
+                stateMutability = "nonpayable";
+            }
+        }
+
+        // @TODO: verifyState for stateMutability (e.g. throw if
+        //        payable: false but stateMutability is "nonpayable")
 
-        return new FunctionFragment(_guard, obj.name, obj.stateMutability,
+        return new FunctionFragment(_guard, obj.name, stateMutability,
              obj.inputs ? obj.inputs.map(ParamType.from): [ ],
              obj.outputs ? obj.outputs.map(ParamType.from): [ ],
              (obj.gas != null) ? obj.gas: null);