feat: add support for Drop node in AST

Adds missing Drop node mapping to AST parser. Includes new test fixture.

Issue: BTC-1826

Author: OttoAllmendinger

packages/wasm-miniscript/js/ast/fromWasmNode.ts

@@ -78,6 +78,8 @@ function fromUnknown(v: unknown): Node | Node[] {
         return wrap("v", value);
       case "ZeroNotEqual":
         return wrap("n", value);
+      case "Drop":
+        return wrap("r", value);
 
       // Conjunctions
       case "AndV":

packages/wasm-miniscript/test/descriptorFixtures.ts

@@ -351,6 +351,12 @@ export const fixtures = {
       script: "51207e8c409f0ab01197f9676efc3a9505f1f09ed0f21693e46a3aa3b6b54d437aa2",
       checksumRequired: true,
     },
+    {
+      descriptor:
+        "wsh(and_v(r:after(1),pkh(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))",
+      script: "0020823bcb22035958d32afe8ec04357535a3e73da3ed9cd90a4251970f9995077a5",
+      checksumRequired: false,
+    },
   ],
   invalid: [
     {

packages/wasm-miniscript/test/fixtures/59.json

@@ -0,0 +1,37 @@
+{
+  "descriptor": "wsh(and_v(r:after(1),pkh(03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204)))#uylapsye",
+  "wasmNode": {
+    "Wsh": {
+      "Ms": {
+        "AndV": [
+          {
+            "Drop": {
+              "After": {
+                "absLockTime": 1
+              }
+            }
+          },
+          {
+            "Check": {
+              "PkH": {
+                "Single": "03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204"
+              }
+            }
+          }
+        ]
+      }
+    }
+  },
+  "ast": {
+    "wsh": {
+      "and_v": [
+        {
+          "r:after": 1
+        },
+        {
+          "pkh": "03cdabb7f2dce7bfbd8a0b9570c6fd1e712e5d64045e9d6b517b3d5072251dc204"
+        }
+      ]
+    }
+  }
+}