node_modules/digitalbits-base/src/asset.js

  1. import {default as xdr} from "./generated/digitalbits-xdr_generated";
  2. import {Keypair} from "./keypair";
  3. import {StrKey} from "./strkey";
  4. import clone from 'lodash/clone';
  5. import padEnd from 'lodash/padEnd';
  6. import trimEnd from 'lodash/trimEnd';
  8. /**
  9.  * Asset class represents an asset, either the native asset (`XLM`)
  10.  * or an asset code / issuer account ID pair.
  11.  *
  12.  * An asset code describes an asset code and issuer pair. In the case of the native
  13.  * asset XLM, the issuer will be null.
  14.  *
  15.  * @constructor
  16.  * @param {string} code - The asset code.
  17.  * @param {string} issuer - The account ID of the issuer.
  18.  */
  19. export class Asset {
  20.   constructor(code, issuer) {
  21.     if (!/^[a-zA-Z0-9]{1,12}$/.test(code)) {
  22.       throw new Error("Asset code is invalid (maximum alphanumeric, 12 characters at max)");
  23.     }
  24.     if (String(code).toLowerCase() !== "xlm" && !issuer) {
  25.       throw new Error("Issuer cannot be null");
  26.     }
  27.     if (issuer && !StrKey.isValidEd25519PublicKey(issuer)) {
  28.       throw new Error("Issuer is invalid");
  29.     }
  31.     this.code = code;
  32.     this.issuer = issuer;
  33.   }
  35.   /**
  36.    * Returns an asset object for the native asset.
  37.    * @Return {Asset}
  38.    */
  39.   static native() {
  40.     return new Asset("XLM");
  41.   }
  43.   /**
  44.    * Returns an asset object from its XDR object representation.
  45.    * @param {xdr.Asset} assetXdr - The asset xdr object.
  46.    * @returns {Asset}
  47.    */
  48.   static fromOperation(assetXdr) {
  49.     let anum, code, issuer;
  50.     switch(assetXdr.switch()) {
  51.       case xdr.AssetType.assetTypeNative():
  52.       return this.native();
  53.       case xdr.AssetType.assetTypeCreditAlphanum4():
  54.       anum = assetXdr.alphaNum4();
  55.       issuer = StrKey.encodeEd25519PublicKey(anum.issuer().ed25519());
  56.       code = trimEnd(anum.assetCode(), '\0');
  57.       return new this(code, issuer);
  58.       case xdr.AssetType.assetTypeCreditAlphanum12():
  59.       anum = assetXdr.alphaNum12();
  60.       issuer = StrKey.encodeEd25519PublicKey(anum.issuer().ed25519());
  61.       code = trimEnd(anum.assetCode(), '\0');
  62.       return new this(code, issuer);
  63.       default:
  64.       throw new Error(`Invalid asset type: ${assetXdr.switch().name}`);
  65.     }
  66.   }
  68.   /**
  69.    * Returns the xdr object for this asset.
  70.    * @returns {xdr.Asset}
  71.    */
  72.   toXDRObject() {
  73.     if (this.isNative()) {
  74.       return xdr.Asset.assetTypeNative();
  75.     } else {
  76.       let xdrType, xdrTypeString;
  77.       if (this.code.length <= 4) {
  78.         xdrType = xdr.AssetAlphaNum4;
  79.         xdrTypeString = 'assetTypeCreditAlphanum4';
  80.       } else {
  81.         xdrType = xdr.AssetAlphaNum12;
  82.         xdrTypeString = 'assetTypeCreditAlphanum12';
  83.       }
  85.           // pad code with null bytes if necessary
  86.           let padLength = this.code.length <= 4 ? 4 : 12;
  87.           let paddedCode = padEnd(this.code, padLength, '\0');
  89.           var assetType = new xdrType({
  90.             assetCode: paddedCode,
  91.             issuer: Keypair.fromPublicKey(this.issuer).xdrAccountId()
  92.           });
  94.           return new xdr.Asset(xdrTypeString, assetType);
  95.         }
  96.       }
  98.   /**
  99.    * Return the asset code
  100.    * @returns {string}
  101.    */
  102.   getCode() {
  103.     return clone(this.code);
  104.   }
  106.   /**
  107.    * Return the asset issuer
  108.    * @returns {string}
  109.    */
  110.   getIssuer() {
  111.     return clone(this.issuer);
  112.   }
  114.   /**
  115.    * Return the asset type. Can be one of following types:
  116.    *
  117.    * * `native`
  118.    * * `credit_alphanum4`
  119.    * * `credit_alphanum12`
  120.    *
  121.    * @see [Assets concept](https://developer.digitalbits.io/learn/concepts/assets.html)
  122.    * @returns {string}
  123.    */
  124.   getAssetType() {
  125.     if (this.isNative()) {
  126.       return 'native';
  127.     } else {
  128.       if (this.code.length >= 1 && this.code.length <= 4) {
  129.         return "credit_alphanum4";
  130.       } else if (this.code.length >= 5 && this.code.length <= 12) {
  131.         return "credit_alphanum12";
  132.       }
  133.     }
  134.   }
  137.   /**
  138.    * Returns true if this asset object is the native asset.
  139.    * @returns {boolean}
  140.    */
  141.   isNative() {
  142.     return !this.issuer;
  143.   }
  145.   /**
  146.    * Returns true if this asset equals the given asset.
  147.    * @param {Asset} asset Asset to compare
  148.    * @returns {boolean}
  149.    */
  150.   equals(asset) {
  151.     return this.code == asset.getCode() && this.issuer == asset.getIssuer();
  152.   }
  153. }