Fix flatten's "not" op handling

Before, `flatten(parse('not a pr'))` would recurse infinitely. Now it
returns the correct result.

Author: markrian

src/flatten.ts

@@ -9,7 +9,7 @@ export const valfilter = (f: Filter, path?: string): Filter => {
     case "or":
       return { ...f, filters: f.filters.map(c => valfilter(c, path)) };
     case "not":
-      return { ...f, filter: valfilter(f, path) };
+      return { ...f, filter: valfilter(f.filter, path) };
     case "[]":
       return valfilter(f.valFilter, f.attrPath);
   }

test/flatten.test.ts

@@ -1,4 +1,4 @@
-import { eq, and, or } from "./test_util";
+import { eq, and, or, not, pr  } from "./test_util";
 import { Filter, parse, flatten } from "../src";
 import { assert } from "chai";
 
@@ -35,6 +35,9 @@ describe("flatten", () => {
       `xx[${e1} and ((${e2} and ${e4}))]`,
       and(eq("xx.n1", 1), eq("xx.n2", 2), eq("xx.n4", 4))
     );
+    test('not a pr', not(pr('a')));
+    test('not a[b pr]', not(pr('a.b')));
+    test('a[not b pr]', not(pr('a.b')));
   });
   describe("andor", () => {
     test(`(${e1} or ${e2}) and ${e3}`, and(or(a1, a2), a3));

test/test_util.ts

@@ -1,4 +1,4 @@
-import { Compare, Filter, ValuePath, Suffix } from "../src";
+import { Compare, Filter, ValuePath, NotFilter, Suffix } from "../src";
 
 export const EOT = { literal: "", type: "EOT" };
 export function eq(attrPath: string, compValue: any): Compare {
@@ -19,3 +19,6 @@ export function v(attrPath: string, valFilter: Filter): ValuePath {
 export function pr(attrPath: string): Suffix {
   return { op: "pr", attrPath };
 }
+export function not(filter: Filter): NotFilter {
+  return { op: "not", filter };
+}