do not throw if name/symbol/decimals differ

src/entities/token.ts

-import { Currency } from './currency'
 import invariant from 'tiny-invariant'
 import { ChainId } from '../constants'
 import { validateAndParseAddress } from '../utils'
+import { Currency } from './currency'
 
 /**
  * Represents an ERC20 token with a unique address and some metadata.
@@ -17,23 +17,15 @@ export class Token extends Currency {
   }
 
   /**
-   * Returns true if the two tokens are equivalent.
+   * Returns true if the two tokens are equivalent, i.e. have the same chainId and address.
    * @param other other token to compare
-   * @throws if the tokens share the address and chain ID but have different metadata
    */
   public equals(other: Token): boolean {
     // short circuit on reference equality
     if (this === other) {
       return true
     }
-    const equivalent = this.chainId === other.chainId && this.address === other.address
-    if (equivalent) {
-      // reference the same token, must have the same decimals/symbol/name
-      invariant(this.decimals === other.decimals, 'DECIMALS')
-      if (this.symbol && other.symbol) invariant(this.symbol === other.symbol, 'SYMBOL')
-      if (this.name && other.name) invariant(this.name === other.name, 'NAME')
-    }
-    return equivalent
+    return this.chainId === other.chainId && this.address === other.address
   }
 
   /**

test/token.test.ts

+import { ChainId, Token } from '../src'
+
+describe('Token', () => {
+  const ADDRESS_ONE = '0x0000000000000000000000000000000000000001'
+  const ADDRESS_TWO = '0x0000000000000000000000000000000000000002'
+
+  describe('#equals', () => {
+    it('fails if address differs', () => {
+      expect(new Token(ChainId.MAINNET, ADDRESS_ONE, 18).equals(new Token(ChainId.MAINNET, ADDRESS_TWO, 18))).toBe(
+        false
+      )
+    })
+
+    it('false if chain id differs', () => {
+      expect(new Token(ChainId.ROPSTEN, ADDRESS_ONE, 18).equals(new Token(ChainId.MAINNET, ADDRESS_ONE, 18))).toBe(
+        false
+      )
+    })
+
+    it('true if only decimals differs', () => {
+      expect(new Token(ChainId.MAINNET, ADDRESS_ONE, 9).equals(new Token(ChainId.MAINNET, ADDRESS_ONE, 18))).toBe(true)
+    })
+
+    it('true if address is the same', () => {
+      expect(new Token(ChainId.MAINNET, ADDRESS_ONE, 18).equals(new Token(ChainId.MAINNET, ADDRESS_ONE, 18))).toBe(true)
+    })
+
+    it('true on reference equality', () => {
+      const token = new Token(ChainId.MAINNET, ADDRESS_ONE, 18)
+      expect(token.equals(token)).toBe(true)
+    })
+
+    it('true even if name/symbol/decimals differ', () => {
+      const tokenA = new Token(ChainId.MAINNET, ADDRESS_ONE, 9, 'abc', 'def')
+      const tokenB = new Token(ChainId.MAINNET, ADDRESS_ONE, 18, 'ghi', 'jkl')
+      expect(tokenA.equals(tokenB)).toBe(true)
+    })
+  })
+})