Add typings for manage_buy_offer.

src/@types/operation.ts

@@ -188,10 +188,6 @@ export namespace Operation {
     offerId: string;
   }
 
-  function manageBuyOffer(
-    options: OperationOptions.ManageBuyOffer
-  ): xdr.Operation<ManageBuyOffer>;
-
   export interface PathPayment extends BaseOperation<OperationType.PathPayment> {
     sendAsset: Asset;
     sendMax: string;

src/operation.ts

@@ -285,7 +285,6 @@ export class Operation extends BaseOperation {
 // TS-TODO: move this to BaseOperation
 Operation.manageData = ops.manageData;
 Operation.manageSellOffer = ops.manageSellOffer;
-Operation.manageBuyOffer = ops.manageBuyOffer;
 Operation.pathPayment = ops.pathPayment;
 Operation.payment = ops.payment;
 Operation.setOptions = ops.setOptions;

src/operations/index.ts

@@ -348,4 +348,50 @@ export abstract class BaseOperation {
     this.setSourceAccount(opAttributes, opts);
     return new xdr.Operation(opAttributes);
   }
+
+  /**
+   * Returns a XDR ManageBuyOfferOp. A "manage buy offer" operation creates, updates, or
+   * deletes a buy offer.
+   * @function
+   * @alias Operation.manageBuyOffer
+   * @param {object} opts Options object
+   * @param {Asset} opts.selling - What you're selling.
+   * @param {Asset} opts.buying - What you're buying.
+   * @param {string} opts.buyAmount - The total amount you're buying. If 0, deletes the offer.
+   * @param {number|string|BigNumber|Object} opts.price - Price of 1 unit of `selling` in terms of `buying`.
+   * @param {number} opts.price.n - If `opts.price` is an object: the price numerator
+   * @param {number} opts.price.d - If `opts.price` is an object: the price denominator
+   * @param {number|string} [opts.offerId ] - If `0`, will create a new offer (default). Otherwise, edits an exisiting offer.
+   * @param {string} [opts.source] - The source account (defaults to transaction source).
+   * @throws {Error} Throws `Error` when the best rational approximation of `price` cannot be found.
+   * @returns {xdr.ManageBuyOfferOp} Manage Buy Offer operation
+   */
+  static manageBuyOffer(opts: OperationOptions.ManageBuyOffer): xdrDef.Operation<Operation.ManageBuyOffer> {
+    const attributes = {};
+    attributes.selling = opts.selling.toXDRObject();
+    attributes.buying = opts.buying.toXDRObject();
+    if (!this.isValidAmount(opts.buyAmount, true)) {
+      throw new TypeError(this.constructAmountRequirementsError('buyAmount'));
+    }
+    attributes.buyAmount = this._toXDRAmount(opts.buyAmount);
+    if (isUndefined(opts.price)) {
+      throw new TypeError('price argument is required');
+    }
+    attributes.price = this._toXDRPrice(opts.price);
+
+    if (!isUndefined(opts.offerId)) {
+      opts.offerId = opts.offerId.toString();
+    } else {
+      opts.offerId = '0';
+    }
+
+    attributes.offerId = Hyper.fromString(opts.offerId);
+    const manageBuyOfferOp = new xdr.ManageBuyOfferOp(attributes);
+
+    const opAttributes = {};
+    opAttributes.body = xdr.OperationBody.manageBuyOffer(manageBuyOfferOp);
+    this.setSourceAccount(opAttributes, opts);
+
+    return new xdr.Operation(opAttributes);
+  }
 }