From d6dbb1bdc80530a7e134df6e4643aed9720e0123 Mon Sep 17 00:00:00 2001
From: Mark Stacey <markjstacey@gmail.com>
Date: Mon, 9 Aug 2021 14:39:54 -0230
Subject: [PATCH] Add `TypedDataUtils.hashType` tests

This function should now be comprehensively tested. These tests mirror
the `TypedDataUtils.encodeType` tests. Any uses of `hashType` in the
older signature tests have been removed, as they are now redundant.
---
 src/index.test.ts | 120 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 92 insertions(+), 28 deletions(-)

diff --git a/src/index.test.ts b/src/index.test.ts
index e2030045..77ef1de2 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -1426,6 +1426,8 @@ describe('TypedDataUtils.encodeData', function () {
 });
 
 describe('TypedDataUtils.encodeType', () => {
+  // Note that these tests should mirror the `TypedDataUtils.hashType` tests. The `hashType`
+  // function just calls `encodeType` and hashes the result.
   it('should encode simple type', () => {
     const types = {
       Person: [{ name: 'name', type: 'string' }],
@@ -1510,6 +1512,96 @@ describe('TypedDataUtils.encodeType', () => {
   });
 });
 
+describe('TypedDataUtils.hashType', () => {
+  // These tests mirror the `TypedDataUtils.encodeType` tests. The same inputs are expected.
+  it('should hash simple type', () => {
+    const types = {
+      Person: [{ name: 'name', type: 'string' }],
+    };
+    const primaryType = 'Person';
+
+    expect(
+      sigUtil.TypedDataUtils.hashType(primaryType, types).toString('hex'),
+    ).toMatchInlineSnapshot(
+      `"fcbb73369ebb221abfdc626fdec0be9ca48ad89ef757b9a76eb7b31ddd261338"`,
+    );
+  });
+
+  it('should hash complex type', () => {
+    const types = {
+      Person: [
+        { name: 'name', type: 'string' },
+        { name: 'wallet', type: 'address' },
+      ],
+      Mail: [
+        { name: 'from', type: 'Person' },
+        { name: 'to', type: 'Person[]' },
+        { name: 'contents', type: 'string' },
+      ],
+    };
+    const primaryType = 'Mail';
+
+    expect(
+      sigUtil.TypedDataUtils.hashType(primaryType, types).toString('hex'),
+    ).toMatchInlineSnapshot(
+      `"dd57d9596af52b430ced3d5b52d4e3d5dccfdf3e0572db1dcf526baad311fbd1"`,
+    );
+  });
+
+  it('should hash recursive type', () => {
+    const types = {
+      Person: [
+        { name: 'name', type: 'string' },
+        { name: 'wallet', type: 'address' },
+      ],
+      Mail: [
+        { name: 'from', type: 'Person' },
+        { name: 'to', type: 'Person' },
+        { name: 'contents', type: 'string' },
+        { name: 'replyTo', type: 'Mail' },
+      ],
+    };
+    const primaryType = 'Mail';
+
+    expect(
+      sigUtil.TypedDataUtils.hashType(primaryType, types).toString('hex'),
+    ).toMatchInlineSnapshot(
+      `"66658e9662034bcd21df657297dab8ba47f0ae05dd8aa253cc935d9aacfd9d10"`,
+    );
+  });
+
+  it('should hash unrecognized types', () => {
+    const types = {
+      Mail: [
+        { name: 'from', type: 'Person' },
+        { name: 'to', type: 'Person' },
+        { name: 'contents', type: 'string' },
+      ],
+    };
+    const primaryType = 'Mail';
+
+    expect(
+      sigUtil.TypedDataUtils.hashType(primaryType, types).toString('hex'),
+    ).toMatchInlineSnapshot(
+      `"c0aee50a43b64ca632347f993c5a39cbddcae6ae329a7a111357622dc88dc1fb"`,
+    );
+  });
+
+  it('should throw if primary type is missing', () => {
+    const types = {
+      Person: [
+        { name: 'name', type: 'string' },
+        { name: 'wallet', type: 'address' },
+      ],
+    };
+    const primaryType = 'Mail';
+
+    expect(() =>
+      sigUtil.TypedDataUtils.hashType(primaryType, types).toString('hex'),
+    ).toThrow('No type definition specified: Mail');
+  });
+});
+
 it('normalize address lower cases', function () {
   const initial = '0xA06599BD35921CfB5B71B4BE3869740385b0B306';
   const result = sigUtil.normalize(initial);
@@ -1977,9 +2069,6 @@ it('signedTypeData', function () {
   const address = ethUtil.privateToAddress(privateKey);
   const sig = sigUtil.signTypedData(privateKey, { data: typedData }, 'V3');
 
-  expect(ethUtil.bufferToHex(utils.hashType('Mail', typedData.types))).toBe(
-    '0xa0cedeb2dc280ba39b857546d74f5549c3a1d7bdc2dd96bf881f76108e23dac2',
-  );
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(
@@ -2056,9 +2145,6 @@ it('signedTypeData with bytes', function () {
     'V3',
   );
 
-  expect(
-    ethUtil.bufferToHex(utils.hashType('Mail', typedDataWithBytes.types)),
-  ).toBe('0x43999c52db673245777eb64b0330105de064e52179581a340a9856c32372528e');
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(
@@ -2144,10 +2230,6 @@ it('signedTypeData_v4', function () {
 
   const utils = sigUtil.TypedDataUtils;
 
-  expect(ethUtil.bufferToHex(utils.hashType('Person', typedData.types))).toBe(
-    '0xfabfe1ed996349fc6027709802be19d047da1aa5d6894ff5f6486d92db2e6860',
-  );
-
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct('Person', typedData.message.from, typedData.types, 'V4'),
@@ -2165,9 +2247,6 @@ it('signedTypeData_v4', function () {
     ),
   ).toBe('0xefa62530c7ae3a290f8a13a5fc20450bdb3a6af19d9d9d2542b5a94e631a9168');
 
-  expect(ethUtil.bufferToHex(utils.hashType('Mail', typedData.types))).toBe(
-    '0x4bd8a9a2b93427bb184aca81e24beb30ffa3c747e2a33d4225ec08bf12e2e753',
-  );
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(
@@ -2255,10 +2334,6 @@ it('signedTypeData_v4', function () {
 
   const utils = sigUtil.TypedDataUtils;
 
-  expect(ethUtil.bufferToHex(utils.hashType('Person', typedData.types))).toBe(
-    '0xfabfe1ed996349fc6027709802be19d047da1aa5d6894ff5f6486d92db2e6860',
-  );
-
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct('Person', typedData.message.from, typedData.types, 'V4'),
@@ -2276,9 +2351,6 @@ it('signedTypeData_v4', function () {
     ),
   ).toBe('0xefa62530c7ae3a290f8a13a5fc20450bdb3a6af19d9d9d2542b5a94e631a9168');
 
-  expect(ethUtil.bufferToHex(utils.hashType('Mail', typedData.types))).toBe(
-    '0x4bd8a9a2b93427bb184aca81e24beb30ffa3c747e2a33d4225ec08bf12e2e753',
-  );
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(
@@ -2353,10 +2425,6 @@ it('signedTypeData_v4 with recursive types', function () {
 
   const utils = sigUtil.TypedDataUtils;
 
-  expect(ethUtil.bufferToHex(utils.hashType('Person', typedData.types))).toBe(
-    '0x7c5c8e90cb92c8da53b893b24962513be98afcf1b57b00327ae4cc14e3a64116',
-  );
-
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(
@@ -2453,10 +2521,6 @@ it('signedTypeMessage V4 with recursive types', function () {
 
   const utils = sigUtil.TypedDataUtils;
 
-  expect(ethUtil.bufferToHex(utils.hashType('Person', typedData.types))).toBe(
-    '0x7c5c8e90cb92c8da53b893b24962513be98afcf1b57b00327ae4cc14e3a64116',
-  );
-
   expect(
     ethUtil.bufferToHex(
       utils.hashStruct(