Shortcuts for Compact/Number instantiation (#4939)

* Shortcuts for Compact/Number instantiation

* Move/combine isHex/isString

packages/types-codec/src/abstract/AbstractInt.ts

@@ -25,15 +25,21 @@ function toPercentage (value: BN, divisor: BN): string {
 }
 
 /** @internal */
-function decodeAbstractInt (value: Exclude<AnyNumber, Uint8Array>, isNegative: boolean): string {
-  if (isBn(value)) {
-    return value.toString();
-  } else if (isHex(value, -1, true)) {
-    return hexToBn(value, { isLe: false, isNegative }).toString();
-  } else if (isNumber(value)) {
+function decodeAbstractInt (value: Exclude<AnyNumber, Uint8Array>, isNegative: boolean): string | number {
+  if (isNumber(value)) {
     assert(value <= Number.MAX_SAFE_INTEGER && value >= Number.MIN_SAFE_INTEGER && Number.isInteger(value), 'Number needs to be an integer <= Number.MAX_SAFE_INTEGER, i.e. 2 ^ 53 - 1');
+
+    return value;
   } else if (isString(value)) {
+    if (isHex(value, -1, true)) {
+      return hexToBn(value, { isLe: false, isNegative }).toString();
+    }
+
     assert(!(value.includes('.') || value.includes(',') || value.includes('e')), 'String should not contain decimal points or scientific notation');
+
+    return value;
+  } else if (isBn(value)) {
+    return value.toString();
   }
 
   return bnToBn(value).toString();

packages/types-codec/src/base/Compact.ts

@@ -5,7 +5,7 @@ import type { BN } from '@polkadot/util';
 import type { HexString } from '@polkadot/util/types';
 import type { AnyJson, AnyNumber, CodecClass, ICompact, Inspect, INumber, IU8a, Registry } from '../types';
 
-import { compactFromU8a, compactToU8a, isU8a } from '@polkadot/util';
+import { compactFromU8a, compactFromU8aLim, compactToU8a, isU8a } from '@polkadot/util';
 
 import { typeToConstructor } from '../utils';
 
@@ -64,11 +64,15 @@ export class Compact<T extends INumber> implements ICompact<T> {
   /** @internal */
   public static decodeCompact<T extends INumber> (registry: Registry, Type: CodecClass<T>, value: Compact<T> | AnyNumber): [T, number] {
     if (isU8a(value)) {
-      const [decodedLength, bn] = compactFromU8a(value);
+      const [decodedLength, bn] = (value[0] & 0b11) < 0b11
+        ? compactFromU8aLim(value)
+        : compactFromU8a(value);
 
       return [new Type(registry, bn), decodedLength];
     } else if (value instanceof Compact) {
-      return [new Type(registry, value.#raw), 0];
+      return value.#raw instanceof Type
+        ? [value.#raw, 0]
+        : [new Type(registry, value.#raw), 0];
     } else if (value instanceof Type) {
       return [value, 0];
     }