fix(sdk): fix evm warp read (#8325)

Author: xeno097

.changeset/fix-fetch-scale-version-check.md

@@ -0,0 +1,5 @@
+---
+"@hyperlane-xyz/sdk": patch
+---
+
+Fixed fetchScale version gate to compare against the contract version where scaling was first introduced (6.0.0) instead of the fraction scaling version (11.0.0), preventing failed scale() reads on pre-scaling contracts.

typescript/sdk/src/token/EvmWarpRouteReader.hardhat-test.ts

@@ -1247,10 +1247,188 @@ describe('EvmWarpRouteReader', async () => {
       });
     }
 
-    // Note: legacy contract fetchScale path (< 11.0.0) cannot be tested in hardhat
-    // without deploying a real legacy contract. The legacy path converts a single
-    // uint256 scale() return to { numerator: bigint, denominator: 1n }.
-    // Coverage is provided by the fetchScale stubs in other tests returning NormalizedScale.
+    // Note: legacy contract fetchScale path (< 11.0.0) is tested via hardhat_setCode
+    // to inject minimal bytecode that responds to the scale() selector.
+    // The legacy path converts a single uint256 scale() return to { numerator: bigint, denominator: 1n }.
+
+    describe('fetchScale', () => {
+      it('should return undefined for contracts before scaling was introduced (< 6.0.0)', async () => {
+        const config: WarpRouteDeployConfigMailboxRequired = {
+          [chain]: {
+            type: TokenType.synthetic,
+            name: TOKEN_NAME,
+            symbol: TOKEN_NAME,
+            decimals: TOKEN_DECIMALS,
+            hook: await mailbox.defaultHook(),
+            ...baseConfig,
+          },
+        };
+
+        const warpRoute = await deployer.deploy(config);
+        const warpAddress = warpRoute[chain].synthetic.address;
+
+        const fetchPackageVersionStub = sinon
+          .stub(evmERC20WarpRouteReader, 'fetchPackageVersion')
+          .resolves('5.0.0');
+
+        const result = await evmERC20WarpRouteReader.fetchScale(warpAddress);
+        expect(result).to.be.undefined;
+
+        fetchPackageVersionStub.restore();
+      });
+
+      it('should read legacy scale() for contracts with version >= 6.0.0 and < 11.0.0', async () => {
+        const expectedScale = 1000n;
+
+        // Deploy a minimal contract that returns expectedScale for scale()
+        // Bytecode: PUSH32 <value> PUSH1 0x00 MSTORE PUSH1 0x20 PUSH1 0x00 RETURN
+        const encodedScale = expectedScale.toString(16).padStart(64, '0');
+        const runtimeBytecode = `0x7f${encodedScale}60005260206000f3`;
+        const mockAddress = '0x' + 'ab'.repeat(20);
+        await hre.network.provider.send('hardhat_setCode', [
+          mockAddress,
+          runtimeBytecode,
+        ]);
+
+        const fetchPackageVersionStub = sinon
+          .stub(evmERC20WarpRouteReader, 'fetchPackageVersion')
+          .resolves('9.0.0');
+
+        const result = await evmERC20WarpRouteReader.fetchScale(mockAddress);
+        expect(result).to.deep.equal({
+          numerator: expectedScale,
+          denominator: 1n,
+        });
+
+        fetchPackageVersionStub.restore();
+      });
+
+      it('should read scaleNumerator/scaleDenominator for contracts >= 11.0.0', async () => {
+        const scaleNumerator = 1;
+        const scaleDenominator = 1000000000000;
+        const config: WarpRouteDeployConfigMailboxRequired = {
+          [chain]: {
+            type: TokenType.synthetic,
+            name: TOKEN_NAME,
+            symbol: TOKEN_NAME,
+            decimals: 6,
+            scale: {
+              numerator: scaleNumerator,
+              denominator: scaleDenominator,
+            },
+            hook: await mailbox.defaultHook(),
+            ...baseConfig,
+          },
+        };
+
+        const warpRoute = await deployer.deploy(config);
+        const warpAddress = warpRoute[chain].synthetic.address;
+
+        const result = await evmERC20WarpRouteReader.fetchScale(warpAddress);
+        expect(result).to.deep.equal({
+          numerator: BigInt(scaleNumerator),
+          denominator: BigInt(scaleDenominator),
+        });
+      });
+
+      it('should read legacy scale() at the exact boundary version 6.0.0', async () => {
+        const expectedScale = 500n;
+
+        const encodedScale = expectedScale.toString(16).padStart(64, '0');
+        const runtimeBytecode = `0x7f${encodedScale}60005260206000f3`;
+        const mockAddress = '0x' + 'ac'.repeat(20);
+        await hre.network.provider.send('hardhat_setCode', [
+          mockAddress,
+          runtimeBytecode,
+        ]);
+
+        const fetchPackageVersionStub = sinon
+          .stub(evmERC20WarpRouteReader, 'fetchPackageVersion')
+          .resolves('6.0.0');
+
+        const result = await evmERC20WarpRouteReader.fetchScale(mockAddress);
+        expect(result).to.deep.equal({
+          numerator: expectedScale,
+          denominator: 1n,
+        });
+
+        fetchPackageVersionStub.restore();
+      });
+
+      it('should read scaleNumerator/scaleDenominator at the exact boundary version 11.0.0', async () => {
+        const scaleNumerator = 1;
+        const scaleDenominator = 1000000000000;
+        const config: WarpRouteDeployConfigMailboxRequired = {
+          [chain]: {
+            type: TokenType.synthetic,
+            name: TOKEN_NAME,
+            symbol: TOKEN_NAME,
+            decimals: 6,
+            scale: {
+              numerator: scaleNumerator,
+              denominator: scaleDenominator,
+            },
+            hook: await mailbox.defaultHook(),
+            ...baseConfig,
+          },
+        };
+
+        const warpRoute = await deployer.deploy(config);
+        const warpAddress = warpRoute[chain].synthetic.address;
+
+        const fetchPackageVersionStub = sinon
+          .stub(evmERC20WarpRouteReader, 'fetchPackageVersion')
+          .resolves('11.0.0');
+
+        const result = await evmERC20WarpRouteReader.fetchScale(warpAddress);
+        expect(result).to.deep.equal({
+          numerator: BigInt(scaleNumerator),
+          denominator: BigInt(scaleDenominator),
+        });
+
+        fetchPackageVersionStub.restore();
+      });
+
+      it('should return undefined for legacy identity scale (scale() = 1)', async () => {
+        const identityScale = 1n;
+
+        const encodedScale = identityScale.toString(16).padStart(64, '0');
+        const runtimeBytecode = `0x7f${encodedScale}60005260206000f3`;
+        const mockAddress = '0x' + 'ad'.repeat(20);
+        await hre.network.provider.send('hardhat_setCode', [
+          mockAddress,
+          runtimeBytecode,
+        ]);
+
+        const fetchPackageVersionStub = sinon
+          .stub(evmERC20WarpRouteReader, 'fetchPackageVersion')
+          .resolves('9.0.0');
+
+        const result = await evmERC20WarpRouteReader.fetchScale(mockAddress);
+        expect(result).to.be.undefined;
+
+        fetchPackageVersionStub.restore();
+      });
+
+      it('should return undefined for identity scale (1/1) on >= 11.0.0 contracts', async () => {
+        const config: WarpRouteDeployConfigMailboxRequired = {
+          [chain]: {
+            type: TokenType.synthetic,
+            name: TOKEN_NAME,
+            symbol: TOKEN_NAME,
+            decimals: TOKEN_DECIMALS,
+            hook: await mailbox.defaultHook(),
+            ...baseConfig,
+          },
+        };
+
+        const warpRoute = await deployer.deploy(config);
+        const warpAddress = warpRoute[chain].synthetic.address;
+
+        const result = await evmERC20WarpRouteReader.fetchScale(warpAddress);
+        expect(result).to.be.undefined;
+      });
+    });
 
     it('should fail when modern version contract claims v10.0.0+ but is missing token() method', async () => {
       const config: WarpRouteDeployConfigMailboxRequired = {

typescript/sdk/src/token/EvmWarpRouteReader.ts

@@ -85,7 +85,14 @@ import { getExtraLockBoxConfigs } from './xerc20.js';
 
 const REBALANCING_CONTRACT_VERSION = '8.0.0';
 export const TOKEN_FEE_CONTRACT_VERSION = '10.0.0';
+
+// version that introduced the fractional scale interface
 const SCALE_FRACTION_VERSION = '11.0.0';
+
+// version that introduced the legacy scale interface
+// https://github.com/hyperlane-xyz/hyperlane-monorepo/releases/tag/%40hyperlane-xyz%2Fcore%406.0.0
+const SCALE_VERSION = '6.0.0';
+
 // Version that first introduced ppm precision for CCTP V2 fee storage (was bps before)
 export const CCTP_PPM_STORAGE_VERSION = '10.2.0';
 // Version that renamed maxFeeBps() to maxFeePpm() on-chain
@@ -1229,14 +1236,19 @@ export class EvmWarpRouteReader extends EvmRouterReader {
     const packageVersion = await this.fetchPackageVersion(tokenRouterAddress);
     const hasScaleFractionInterface =
       compareVersions(packageVersion, SCALE_FRACTION_VERSION) >= 0;
+    const hasScaleInterface =
+      compareVersions(packageVersion, SCALE_VERSION) >= 0;
+
+    if (!hasScaleFractionInterface && !hasScaleInterface) {
+      return;
+    }
 
     const tokenRouter = TokenRouter__factory.connect(
       tokenRouterAddress,
       this.provider,
     );
 
     let result: NormalizedScale;
-
     if (hasScaleFractionInterface) {
       // Read new format (scaleNumerator and scaleDenominator)
       const [numerator, denominator] = await Promise.all([