Implement host API for big decimal equals (#476)

* Implement host api for big decimal equals

* Add test cases for big decimal equals

* Use boolean type conversion

---------

Co-authored-by: neeraj <neeraj.rtly@gmail.com>

packages/graph-node/src/loader.ts

@@ -478,7 +478,23 @@ export const instantiate = async (
 
         return powResultBigDecimal;
       },
+      'bigDecimal.equals': async (x: number, y: number) => {
+        // Create decimal x string.
+        const xBigDecimal = await BigDecimal.wrap(x);
+        const xStringPtr = await xBigDecimal.toString();
+        const xDecimalString = __getString(xStringPtr);
+        const xDecimal = new GraphDecimal(xDecimalString);
 
+        // Create decimal y string.
+        const yBigDecimal = await BigDecimal.wrap(y);
+        const yStringPtr = await yBigDecimal.toString();
+        const yDecimalString = __getString(yStringPtr);
+
+        // Perform the decimal equal operation.
+        const isEqual = xDecimal.equals(yDecimalString);
+
+        return isEqual;
+      },
       'bigInt.fromString': async (s: number) => {
         const string = __getString(s);
 

packages/graph-node/src/numbers.test.ts

@@ -638,4 +638,22 @@ describe('numbers wasm tests', () => {
       expect(__getString(ptr)).to.equal(expected);
     });
   });
+
+  describe('should execute bigDecimal equals API', () => {
+    let testBigDecimalEquals: any, __newString: any;
+
+    before(() => {
+      ({ testBigDecimalEquals, __newString } = exports);
+    });
+
+    it('should check given bigDecimals are equal', async () => {
+      const ptr = await testBigDecimalEquals(await __newString('231543212.2132354'), await __newString('231543212.2132354'));
+      expect(Boolean(ptr)).to.equal(true);
+    });
+
+    it('should check given bigDecimals are not equal', async () => {
+      const ptr = await testBigDecimalEquals(await __newString('231543212.2132354'), await __newString('54652.65645'));
+      expect(Boolean(ptr)).to.equal(false);
+    });
+  });
 });

packages/graph-node/test/subgraph/example1/src/mapping.ts

@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 
-import { Address, log, BigInt, BigDecimal, ByteArray, dataSource, ethereum, Bytes, crypto, json, JSONValueKind } from '@graphprotocol/graph-ts';
+import { Address, log, BigInt, BigDecimal, bigDecimal, ByteArray, dataSource, ethereum, Bytes, crypto, json, JSONValueKind } from '@graphprotocol/graph-ts';
 
 import {
   Example1,
@@ -299,6 +299,15 @@ export function testBigDecimalTimes (value1: string, value2: string): string {
   return res.toString();
 }
 
+export function testBigDecimalEquals (value1: string, value2: string): boolean {
+  log.debug('In test bigDecimal.equals', []);
+
+  const bigDecimal1 = bigDecimal.fromString(value1);
+  const bigDecimal2 = bigDecimal.fromString(value2);
+
+  return bigDecimal1.equals(bigDecimal2);
+}
+
 export function testBigIntPlus (value1: string, value2: string): string {
   log.debug('In test bigInt.plus', []);
 

packages/util/src/graph/graph-decimal.ts

@@ -151,6 +151,13 @@ export class GraphDecimal {
     return this.value.cmp(param);
   }
 
+  equals (n: Decimal.Value | GraphDecimal): boolean {
+    this._checkOutOfRange(this);
+    const param = this._checkOutOfRange(n);
+
+    return this.value.equals(param);
+  }
+
   /**
    * Function to check and throw an error if a given value has exponent out of the specified range (MIN_EXP to MAX_EXP).
    * @param n A Decimal value to check the range for.