Add BitVec.toBoolArray() helper function (#5585)

packages/types-codec/src/extended/BitVec.spec.ts

@@ -48,6 +48,44 @@ describe('BitVec', (): void => {
     });
   });
 
+  describe('toBoolArray() ordering', (): void => {
+    it('defaults to Lsb', (): void => {
+      expect(
+        new BitVec(registry, '0x0100010500').toBoolArray()
+      ).toEqual([
+        true, false, false, false, false, false, false, false,
+        false, false, false, false, false, false, false, false,
+        true, false, false, false, false, false, false, false,
+        true, false, true, false, false, false, false, false,
+        false, false, false, false, false, false, false, false
+      ]);
+    });
+
+    it('can output to Msb', (): void => {
+      expect(
+        new BitVec(registry, '0x0100010500', true).toBoolArray()
+      ).toEqual([
+        false, false, false, false, false, false, false, true,
+        false, false, false, false, false, false, false, false,
+        false, false, false, false, false, false, false, true,
+        false, false, false, false, false, true, false, true,
+        false, false, false, false, false, false, false, false
+      ]);
+    });
+
+    it('outputs all LSB bits', (): void => {
+      expect(
+        new BitVec(registry, '0x01000105ff').toBoolArray()
+      ).toEqual([
+        true, false, false, false, false, false, false, false,
+        false, false, false, false, false, false, false, false,
+        true, false, false, false, false, false, false, false,
+        true, false, true, false, false, false, false, false,
+        true, true, true, true, true, true, true, true
+      ]);
+    });
+  });
+
   it('has a sane inspect', (): void => {
     expect(
       new BitVec(registry, '0x0837').inspect()

packages/types-codec/src/extended/BitVec.ts

@@ -73,6 +73,36 @@ export class BitVec extends Raw {
     };
   }
 
+  /**
+   * @description Creates a boolean array of the bit values
+   */
+  public toBoolArray (): boolean[] {
+    const map = [...this.toU8a(true)].map((v) => [
+      !!(v & 0b1000_0000),
+      !!(v & 0b0100_0000),
+      !!(v & 0b0010_0000),
+      !!(v & 0b0001_0000),
+      !!(v & 0b0000_1000),
+      !!(v & 0b0000_0100),
+      !!(v & 0b0000_0010),
+      !!(v & 0b0000_0001)
+    ]);
+    const result = new Array<boolean>(8 * map.length);
+
+    for (let i = 0; i < map.length; i++) {
+      const off = i * 8;
+      const v = map[i];
+
+      for (let j = 0; j < 8; j++) {
+        result[off + j] = this.#isMsb
+          ? v[j]
+          : v[7 - j];
+      }
+    }
+
+    return result;
+  }
+
   /**
    * @description Converts the Object to to a human-friendly JSON, with additional fields, expansion and formatting of information
    */

packages/types/src/metadata/PortableRegistry/PortableRegistry.ts

@@ -722,15 +722,22 @@ export class PortableRegistry extends Struct implements ILookup {
       ? [a, b]
       : [b, a];
 
-    // NOTE: Currently the BitVec type is one-way only, i.e. we only use it to decode, not
-    // re-encode stuff. As such we ignore the msb/lsb identifier given by bitOrderType, or rather
-    // we don't pass it though at all (all displays in LSB)
-    if (!BITVEC_NS.includes(bitOrder.namespace || '')) {
+    if (!bitOrder.namespace || !BITVEC_NS.includes(bitOrder.namespace)) {
       throw new Error(`Unexpected bitOrder found as ${bitOrder.namespace || '<unknown>'}`);
     } else if (bitStore.info !== TypeDefInfo.Plain || bitStore.type !== 'u8') {
       throw new Error(`Only u8 bitStore is currently supported, found ${bitStore.type}`);
     }
 
+    const isLsb = BITVEC_NS_LSB.includes(bitOrder.namespace);
+
+    if (!isLsb) {
+      // TODO To remove this limitation, we need to pass an extra info flag
+      // through to the TypeDef (Here we could potentially re-use something
+      // like index (???) to indicate and ensure we use it to pass to the
+      // BitVec constructor - which does handle this type)
+      throw new Error(`Only LSB BitVec is currently supported, found ${bitOrder.namespace}`);
+    }
+
     return {
       info: TypeDefInfo.Plain,
       type: 'BitVec'