Add AddressToUintMap (#3150)

* add AddressToUintMap

* Update contracts/utils/structs/EnumerableMap.sol

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

* address comments

* lint code

* merge mocks into a single file

* add PR link to changelog entry

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>
Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>

.prettierrc

 {
+  "singleQuote": true,
+  "trailingComma": "all",
   "overrides": [
     {
       "files": "*.sol",
       "options": {
+        "singleQuote": false,
         "printWidth": 120,
         "explicitTypes": "always"
       }

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
  * `AccessControl`: add a virtual `_checkRole(bytes32)` function that can be overriden to alter the `onlyRole` modifier behavior. ([#3137](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3137))
+ * `EnumerableMap`: add new `AddressToUintMap` map type. ([#3150](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3150))
 
 ## Unreleased
 

contracts/mocks/EnumerableMapMock.sol

@@ -4,7 +4,8 @@ pragma solidity ^0.8.0;
 
 import "../utils/structs/EnumerableMap.sol";
 
-contract EnumerableMapMock {
+// UintToAddressMap
+contract UintToAddressMapMock {
     using EnumerableMap for EnumerableMap.UintToAddressMap;
 
     event OperationResult(bool result);
@@ -45,3 +46,42 @@ contract EnumerableMapMock {
         return _map.get(key, errorMessage);
     }
 }
+
+// AddressToUintMap
+contract AddressToUintMapMock {
+    using EnumerableMap for EnumerableMap.AddressToUintMap;
+
+    event OperationResult(bool result);
+
+    EnumerableMap.AddressToUintMap private _map;
+
+    function contains(address key) public view returns (bool) {
+        return _map.contains(key);
+    }
+
+    function set(address key, uint256 value) public {
+        bool result = _map.set(key, value);
+        emit OperationResult(result);
+    }
+
+    function remove(address key) public {
+        bool result = _map.remove(key);
+        emit OperationResult(result);
+    }
+
+    function length() public view returns (uint256) {
+        return _map.length();
+    }
+
+    function at(uint256 index) public view returns (address key, uint256 value) {
+        return _map.at(index);
+    }
+
+    function tryGet(address key) public view returns (bool, uint256) {
+        return _map.tryGet(key);
+    }
+
+    function get(address key) public view returns (uint256) {
+        return _map.get(key);
+    }
+}

contracts/utils/structs/EnumerableMap.sol

@@ -26,8 +26,10 @@ import "./EnumerableSet.sol";
  * }
  * ```
  *
- * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
- * supported.
+ * The following map types are supported:
+ *
+ * - `uint256 -> address` (`UintToAddressMap`) since v3.0.0
+ * - `address -> uint256` (`AddressToUintMap`) since v4.6.0
  */
 library EnumerableMap {
     using EnumerableSet for EnumerableSet.Bytes32Set;
@@ -237,4 +239,84 @@ library EnumerableMap {
     ) internal view returns (address) {
         return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
     }
+
+    // AddressToUintMap
+
+    struct AddressToUintMap {
+        Map _inner;
+    }
+
+    /**
+     * @dev Adds a key-value pair to a map, or updates the value for an existing
+     * key. O(1).
+     *
+     * Returns true if the key was added to the map, that is if it was not
+     * already present.
+     */
+    function set(
+        AddressToUintMap storage map,
+        address key,
+        uint256 value
+    ) internal returns (bool) {
+        return _set(map._inner, bytes32(uint256(uint160(key))), bytes32(value));
+    }
+
+    /**
+     * @dev Removes a value from a set. O(1).
+     *
+     * Returns true if the key was removed from the map, that is if it was present.
+     */
+    function remove(AddressToUintMap storage map, address key) internal returns (bool) {
+        return _remove(map._inner, bytes32(uint256(uint160(key))));
+    }
+
+    /**
+     * @dev Returns true if the key is in the map. O(1).
+     */
+    function contains(AddressToUintMap storage map, address key) internal view returns (bool) {
+        return _contains(map._inner, bytes32(uint256(uint160(key))));
+    }
+
+    /**
+     * @dev Returns the number of elements in the map. O(1).
+     */
+    function length(AddressToUintMap storage map) internal view returns (uint256) {
+        return _length(map._inner);
+    }
+
+    /**
+     * @dev Returns the element stored at position `index` in the set. O(1).
+     * Note that there are no guarantees on the ordering of values inside the
+     * array, and it may change when more values are added or removed.
+     *
+     * Requirements:
+     *
+     * - `index` must be strictly less than {length}.
+     */
+    function at(AddressToUintMap storage map, uint256 index) internal view returns (address, uint256) {
+        (bytes32 key, bytes32 value) = _at(map._inner, index);
+        return (address(uint160(uint256(key))), uint256(value));
+    }
+
+    /**
+     * @dev Tries to returns the value associated with `key`.  O(1).
+     * Does not revert if `key` is not in the map.
+     *
+     * _Available since v3.4._
+     */
+    function tryGet(AddressToUintMap storage map, address key) internal view returns (bool, uint256) {
+        (bool success, bytes32 value) = _tryGet(map._inner, bytes32(uint256(uint160(key))));
+        return (success, uint256(value));
+    }
+
+    /**
+     * @dev Returns the value associated with `key`.  O(1).
+     *
+     * Requirements:
+     *
+     * - `key` must be in the map.
+     */
+    function get(AddressToUintMap storage map, address key) internal view returns (uint256) {
+        return uint256(_get(map._inner, bytes32(uint256(uint160(key)))));
+    }
 }

test/utils/structs/EnumerableMap/AddressToUintMap.test.js

+const { BN, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
+const { expect } = require('chai');
+const { expectMembersMatch } = require('./helpers');
+
+const AddressToUintMapMock = artifacts.require('AddressToUintMapMock');
+
+contract('AddressToUintMap', function (accounts) {
+  const [accountA, accountB, accountC] = accounts;
+
+  const valueA = new BN('7891');
+  const valueB = new BN('451');
+  const valueC = new BN('9592328');
+
+  beforeEach(async function () {
+    this.map = await AddressToUintMapMock.new();
+  });
+
+  it('starts empty', async function () {
+    expect(await this.map.contains(accountA)).to.equal(false);
+
+    await expectMembersMatch(this.map, [], []);
+  });
+
+  describe('set', function () {
+    it('adds a key', async function () {
+      const receipt = await this.map.set(accountA, valueA);
+
+      expectEvent(receipt, 'OperationResult', { result: true });
+
+      await expectMembersMatch(this.map, [accountA], [valueA]);
+    });
+
+    it('adds several keys', async function () {
+      await this.map.set(accountA, valueA);
+      await this.map.set(accountB, valueB);
+
+      await expectMembersMatch(this.map, [accountA, accountB], [valueA, valueB]);
+
+      expect(await this.map.contains(accountC)).to.equal(false);
+    });
+
+    it('returns false when adding keys already in the set', async function () {
+      await this.map.set(accountA, valueA);
+
+      const receipt = await this.map.set(accountA, valueA);
+
+      expectEvent(receipt, 'OperationResult', { result: false });
+
+      await expectMembersMatch(this.map, [accountA], [valueA]);
+    });
+
+    it('updates values for keys already in the set', async function () {
+      await this.map.set(accountA, valueA);
+      await this.map.set(accountA, valueB);
+
+      await expectMembersMatch(this.map, [accountA], [valueB]);
+    });
+  });
+
+  describe('remove', function () {
+    it('removes added keys', async function () {
+      await this.map.set(accountA, valueA);
+
+      const receipt = await this.map.remove(accountA);
+
+      expectEvent(receipt, 'OperationResult', { result: true });
+
+      expect(await this.map.contains(accountA)).to.equal(false);
+
+      await expectMembersMatch(this.map, [], []);
+    });
+
+    it('returns false when removing keys not in the set', async function () {
+      const receipt = await this.map.remove(accountA);
+
+      expectEvent(receipt, 'OperationResult', { result: false });
+
+      expect(await this.map.contains(accountA)).to.equal(false);
+    });
+
+    it('adds and removes multiple keys', async function () {
+      // []
+
+      await this.map.set(accountA, valueA);
+      await this.map.set(accountC, valueC);
+
+      // [A, C]
+
+      await this.map.remove(accountA);
+      await this.map.remove(accountB);
+
+      // [C]
+
+      await this.map.set(accountB, valueB);
+
+      // [C, B]
+
+      await this.map.set(accountA, valueA);
+      await this.map.remove(accountC);
+
+      // [A, B]
+
+      await this.map.set(accountA, valueA);
+      await this.map.set(accountB, valueB);
+
+      // [A, B]
+
+      await this.map.set(accountC, valueC);
+      await this.map.remove(accountA);
+
+      // [B, C]
+
+      await this.map.set(accountA, valueA);
+      await this.map.remove(accountB);
+
+      // [A, C]
+
+      await expectMembersMatch(this.map, [accountA, accountC], [valueA, valueC]);
+
+      expect(await this.map.contains(accountB)).to.equal(false);
+    });
+  });
+
+  describe('read', function () {
+    beforeEach(async function () {
+      await this.map.set(accountA, valueA);
+    });
+
+    describe('get', function () {
+      it('existing value', async function () {
+        expect(await this.map.get(accountA)).to.bignumber.equal(valueA);
+      });
+
+      it('missing value', async function () {
+        await expectRevert(this.map.get(accountB), 'EnumerableMap: nonexistent key');
+      });
+    });
+
+    describe('tryGet', function () {
+      const stringifyTryGetValue = ({ 0: result, 1: value }) => ({ 0: result, 1: value.toString() });
+
+      it('existing value', async function () {
+        const actual = stringifyTryGetValue(await this.map.tryGet(accountA));
+        const expected = stringifyTryGetValue({ 0: true, 1: valueA });
+
+        expect(actual).to.deep.equal(expected);
+      });
+
+      it('missing value', async function () {
+        const actual = stringifyTryGetValue(await this.map.tryGet(accountB));
+        const expected = stringifyTryGetValue({ 0: false, 1: new BN('0') });
+
+        expect(actual).to.deep.equal(expected);
+      });
+    });
+  });
+});

test/utils/structs/EnumerableMap.test.js → test/utils/structs/EnumerableMap/UintToAddressMap.test.js

 const { BN, constants, expectEvent, expectRevert } = require('@openzeppelin/test-helpers');
 const { expect } = require('chai');
+const { expectMembersMatch } = require('./helpers');
 
-const zip = require('lodash.zip');
+const UintToAddressMapMock = artifacts.require('UintToAddressMapMock');
 
-const EnumerableMapMock = artifacts.require('EnumerableMapMock');
-
-contract('EnumerableMap', function (accounts) {
-  const [ accountA, accountB, accountC ] = accounts;
+contract('UintToAddressMap', function (accounts) {
+  const [accountA, accountB, accountC] = accounts;
 
   const keyA = new BN('7891');
   const keyB = new BN('451');
   const keyC = new BN('9592328');
 
   beforeEach(async function () {
-    this.map = await EnumerableMapMock.new();
+    this.map = await UintToAddressMapMock.new();
   });
 
-  async function expectMembersMatch (map, keys, values) {
-    expect(keys.length).to.equal(values.length);
-
-    await Promise.all(keys.map(async key =>
-      expect(await map.contains(key)).to.equal(true),
-    ));
-
-    expect(await map.length()).to.bignumber.equal(keys.length.toString());
-
-    expect(await Promise.all(keys.map(key =>
-      map.get(key),
-    ))).to.have.same.members(values);
-
-    // To compare key-value pairs, we zip keys and values, and convert BNs to
-    // strings to workaround Chai limitations when dealing with nested arrays
-    expect(await Promise.all([...Array(keys.length).keys()].map(async (index) => {
-      const entry = await map.at(index);
-      return [entry.key.toString(), entry.value];
-    }))).to.have.same.deep.members(
-      zip(keys.map(k => k.toString()), values),
-    );
-  }
-
   it('starts empty', async function () {
     expect(await this.map.contains(keyA)).to.equal(false);
 
@@ -64,7 +40,7 @@ contract('EnumerableMap', function (accounts) {
     it('returns false when adding keys already in the set', async function () {
       await this.map.set(keyA, accountA);
 
-      const receipt = (await this.map.set(keyA, accountA));
+      const receipt = await this.map.set(keyA, accountA);
       expectEvent(receipt, 'OperationResult', { result: false });
 
       await expectMembersMatch(this.map, [keyA], [accountA]);

test/utils/structs/EnumerableMap/helpers.js

+const zip = require('lodash.zip');
+
+const toStringArray = (array) => array.map((i) => i.toString());
+
+async function expectMembersMatch (map, keys, values) {
+  const stringKeys = toStringArray(keys);
+  const stringValues = toStringArray(values);
+
+  expect(keys.length).to.equal(values.length);
+
+  await Promise.all(keys.map(async (key) => expect(await map.contains(key)).to.equal(true)));
+
+  expect(await map.length()).to.bignumber.equal(keys.length.toString());
+
+  expect(toStringArray(await Promise.all(keys.map((key) => map.get(key))))).to.have.same.members(stringValues);
+
+  // to compare key-value pairs, we zip keys and values
+  // we also stringify pairs because this helper is used for multiple types of maps
+  expect(
+    await Promise.all(
+      [...Array(keys.length).keys()].map(async (index) => {
+        const { key, value } = await map.at(index);
+        return [key.toString(), value.toString()];
+      }),
+    ),
+  ).to.have.same.deep.members(zip(stringKeys, stringValues));
+}
+
+module.exports = {
+  expectMembersMatch,
+};