Set assert fix (with tests) (#925)

* Set assert fix (with tests)

* toNumber() -> function

packages/types/src/codec/Set.spec.ts

@@ -17,6 +17,12 @@ const SET_ROLES = {
   light:     0b00000010,
   authority: 0b00000100
 };
+const SET_WITHDRAW = {
+  TransactionPayment: 0b00000001,
+  Transfer: 0b00000010,
+  Reserve: 0b00000100,
+  Fee: 0b00001000
+};
 
 describe('Set', () => {
   it('constructs via an Array<string>', () => {
@@ -40,13 +46,16 @@ describe('Set', () => {
     ).toThrow(/Invalid key 'invalid'/);
   });
 
-  it('constructs via Uint8Array', () => {
-    const set = new Set(SET_FIELDS, new Uint8Array([0b00000001 | 0b00000010 | 0b00010000 | 0b10000000]));
+  it('allows construction via number', () => {
+    expect(
+      (new Set(SET_WITHDRAW, 15)).eq(['TransactionPayment', 'Transfer', 'Reserve', 'Fee'])
+    ).toBe(true);
+  });
 
-    expect(set.encodedLength).toEqual(1);
-    expect(set.toJSON()).toEqual([
-      'header', 'body', 'justification'
-    ]);
+  it('does not allow invalid number', () => {
+    expect(
+      () => new Set(SET_WITHDRAW, 31)
+    ).toThrow(/Mismatch decoding '31', computed as '15'/);
   });
 
   it('hash a valid encoding', () => {

packages/types/src/codec/Set.ts

@@ -56,7 +56,7 @@ export default class CodecSet extends Set<string> implements Codec {
 
     const computed = CodecSet.encodeSet(setValues, result);
 
-    assert(value !== computed, `Set: Mismatch decoding '${value}', computed as '${computed}' with ${result}`);
+    assert(value === computed, `Set: Mismatch decoding '${value}', computed as '${computed}' with ${result}`);
 
     return result;
   }
@@ -138,6 +138,13 @@ export default class CodecSet extends Set<string> implements Codec {
     return this.strings;
   }
 
+  /**
+   * @description The encoded value for the set members
+   */
+  toNumber (): number {
+    return this.valueEncoded;
+  }
+
   /**
    * @description Returns the base runtime type name for this instance
    */