wasm: Allow arbitrary predicates in queries

lib/binding_web/test/query-test.js

@@ -45,9 +45,6 @@ describe("Query", () => {
       assert.throws(() => {
         JavaScript.query("((identifier) @a (eq? @a @a @a))");
       }, "Wrong number of arguments to `#eq?` predicate. Expected 2, got 3");
-      assert.throws(() => {
-        JavaScript.query("((identifier) @a (#something-else? @a))");
-      }, "Unknown query predicate `#something-else?`");
     });
   });
 
@@ -207,6 +204,52 @@ describe("Query", () => {
       ]);
     });
   });
+
+  describe(".predicatesForPattern(index)", () => {
+    it("returns all of the predicates as objects", () => {
+      query = JavaScript.query(`
+        (
+          (binary_expression
+            left: (identifier) @a
+            right: (identifier) @b)
+          (#something? @a @b)
+          (#match? @a "c")
+          (#something-else? @a "A" @b "B")
+        )
+
+        ((identifier) @c
+         (#hello! @c))
+
+        "if" @d
+      `);
+
+      assert.deepEqual(query.predicatesForPattern(0), [
+        {
+          operator: "something?",
+          operands: [
+            { type: "capture", name: "a" },
+            { type: "capture", name: "b" },
+          ],
+        },
+        {
+          operator: "something-else?",
+          operands: [
+            { type: "capture", name: "a" },
+            { type: "string", value: "A" },
+            { type: "capture", name: "b" },
+            { type: "string", value: "B" },
+          ],
+        },
+      ]);
+      assert.deepEqual(query.predicatesForPattern(1), [
+        {
+          operator: "hello!",
+          operands: [{ type: "capture", name: "c" }],
+        },
+      ]);
+      assert.deepEqual(query.predicatesForPattern(2), []);
+    });
+  });
 });
 
 function formatMatches(matches) {