Web3 social media project

web3_social_media/README.md

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+# Social Media Smart Contract
+- Note: This project include an [article](https://medium.com/@aycrown77/resolving-a-getcontractfactory-error-in-hardhat-a-step-by-step-guide-d901fc186815) on how I was able to resolve the deployment error I was facing.
+## Overview
+
+This Ethereum smart contract functions as a basic social media platform, allowing users to create posts, like posts created by others, and view their own and other users' posts.
+
+## Prerequisites
+
+- An Ethereum wallet and access to a blockchain network (i.e Buildbear Etherium testnet) with sufficient ETH for transaction fees.
+- An Ethereum development environment, such as Remix or a development framework like Truffle.
+- Solidity compiler version 0.8.13 or compatible.
+
+## Contract Details
+
+- **Solidity Version**: ^0.8.13
+- **Owner**: The owner of this contract is set at deployment and is the Ethereum address that deploys it. The owner has special privileges, such as changing the maximum post length.
+
+## Features
+
+### 1. Create Post
+
+- **Function**: `createPost(string memory _post)`
+- Allows a user to create a new post.
+- Verifies that the post length does not exceed the maximum allowed length (`MAX_POST_LENGHT`).
+- Emits a `postCreated` event upon successful post creation.
+
+### 2. Like Post
+
+- **Function**: `likeTweet(address author, uint256 id) external`
+- Allows a user to like a post created by another user.
+- Emits a `postLiked` event upon successful liking.
+
+### 3. Unlike Post
+
+- **Function**: `unlikeTweet(address author, uint256 id) external`
+- Allows a user to unlike a post they had previously liked.
+- Emits a `postUnliked` event upon successful unliking.
+
+### 4. Get Post
+
+- **Function**: `getPost(uint _i) public view returns (Post memory)`
+- Retrieves a specific post created by the calling user.
+
+### 5. Get All Posts
+
+- **Function**: `getAllPost(address _owner) public view returns (Post[] memory)`
+- Retrieves all posts created by a specific user.
+
+### 6. Change Post Length
+
+- **Function**: `changePostLength(uint16 newPostLength) public onlyOwner`
+- Allows the owner to change the maximum allowed post length.
+
+## Events
+
+- `postCreated(uint256 id, address author, string content, uint256 timestamp)`
+  - Emitted when a new post is created.
+
+- `postLiked(address liker, address postAuthor, uint256 postId, uint256 newLikeCount)`
+  - Emitted when a post is liked.
+
+- `postUnliked(address unliker, address postAuthor, uint256 postId, uint256 newLikedCount)`
+  - Emitted when a like on a post is removed.
+
+## Usage
+
+1. **Deployment**
+   - Deploy the contract using a compatible Ethereum development environment.
+   - Due to the issues I faced while trying to deploy my smart contract, I wrote an article on how I was able to overcome the challenge
+   - Here is the link to the article: https://medium.com/@aycrown77/resolving-a-getcontractfactory-error-in-hardhat-a-step-by-step-guide-d901fc186815
+
+2. **Creating a Post**
+   - Use the `createPost` function to create a new post.
+
+3. **Liking a Post**
+   - Use the `likeTweet` function, providing the author's address and the post ID.
+
+4. **Unliking a Post**
+   - Use the `unlikeTweet` function, providing the author's address and the post ID.
+
+5. **Viewing Posts**
+   - Use the `getPost` or `getAllPost` functions to view posts.
+
+6. **Changing Post Length (Owner only)**
+   - Use the `changePostLength` function to adjust the maximum post length.
+
+## Notes
+
+- Ensure that the maximum post length (`MAX_POST_LENGHT`) is set to a reasonable value to prevent excessive gas costs for long posts.
+
+## Disclaimer
+
+- This smart contract is provided as-is. The owners and developers are not responsible for any issues, bugs, or misuse that may occur while using this contract.
+
+## License
+
+This smart contract is released under the [MIT License](LICENSE).

web3_social_media/contracts/SocialMedial.sol

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+// SPDX-License-Identifier: MIT
+// web3 Social media smart contract
+pragma solidity ^0.8.13;
+
+contract SocialMedia {
+
+    uint16 public MAX_POST_LENGHT = 200;
+    address public owner;
+
+    // define Post struct
+    struct Post {
+        uint256 id;
+        address author;
+        string content;
+        uint256 timestamp;
+        uint256 likes;
+    }
+    // maps user to post
+    mapping(address => Post[]) public posts;
+
+    // Define the events
+    event postCreated(uint256 id, address author, 
+                    string content, uint256 timestamp);
+    event postLiked(address liker, address postAuthor, 
+                    uint256 postId, uint256 newLikeCount);
+    event postUnliked(address unliker, address postAuthor, 
+                    uint256 postId, uint256 newLikedCount);
+
+    //constructor to set an owner of the contract
+    constructor() {
+        owner = msg.sender;
+    }
+
+    //Modifier to verify the real owner
+    modifier onlyOwner() {
+        require(msg.sender == owner, "YOU ARE NOT THE OWNER OF THE CONTRACT");
+        _;
+    }
+
+    // Adds a post to the user
+    function createPost(string memory _post) public {
+        //check if post length <= 200, continue, otherwise revert
+        require(bytes(_post).length <= MAX_POST_LENGHT, "Post too long!");
+        Post memory newPost = Post({
+            id: posts[msg.sender].length,
+            author: msg.sender,
+            content: _post,
+            timestamp: block.timestamp,
+            likes: 0
+        });
+        posts[msg.sender].push(newPost);
+
+        emit postCreated(newPost.id, newPost.author, newPost.content, newPost.timestamp);
+    }
+
+    // like a post
+    function likeTweet(address author, uint256 id) external {
+        require(posts[author][id].id == id, "post does not exist");
+        posts[author][id].likes++;
+        uint256 newLikeCount = posts[author][id].likes;
+
+        emit postLiked(msg.sender, author, id, newLikeCount);
+    }
+
+    // Unlike the post
+    function unlikeTweet(address author, uint256 id) external {
+        require(posts[author][id].id == id, "Post does not exist");
+        require(posts[author][id].likes > 0, "Post has no likes");
+
+        posts[author][id].likes--;
+
+        uint256 newLikeCount = posts[author][id].likes;
+        emit postUnliked(msg.sender, author, id, newLikeCount);
+    }
+
+    // Gets post from the user
+    function getPost(uint _i) public view returns (Post memory){
+        return posts[msg.sender][_i];
+    }
+
+    // Gets all post from the user
+    function getAllPost(address _owner) public view returns (Post[] memory){
+       return posts[_owner];
+    }
+
+    // Changes the length of post
+    function changePostLength(uint16 newPostLength) public onlyOwner{
+        MAX_POST_LENGHT = newPostLength;
+    }
+
+}

web3_social_media/hardhat.config.js

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+require("@nomicfoundation/hardhat-toolbox");
+
+/** @type import('hardhat/config').HardhatUserConfig */
+module.exports = {
+  solidity: "0.8.13",
+  networks: {
+    buildbear: {
+      url: "https://rpc.buildbear.io/marxist-rugor-nass-cbb8c77f",
+    },
+  },
+};

web3_social_media/package.json

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+{
+  "name": "web3_social_media",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@openzeppelin/contracts": "^4.9.3"
+  },
+  "devDependencies": {
+    "@nomicfoundation/hardhat-toolbox": "^1.0.2",
+    "hardhat": "^2.17.3"
+  }
+}

web3_social_media/scripts/deploy.js

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+const hre = require("hardhat");
+
+async function main() {
+    const SocialMedia = await hre.ethers.getContractFactory("SocialMedia");
+    const socialMedia = await SocialMedia.deploy();
+
+    await socialMedia.deployed();
+
+    console.log("SocialMedia deployed to:", socialMedia.address);
+  }
+
+  main()
+    .then(() => process.exit(0))
+    .catch((error) => {
+      console.error(error);
+      process.exit(1);
+    });

web3_social_media/scripts/test/socialMedia.test.js

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+const SocialMedia = artifacts.require("SocialMedia");
+
+contract("SocialMedia", (accounts) => {
+    let socialMediaInstance;
+
+    beforeEach(async () => {
+        socialMediaInstance = await SocialMedia.new();
+    });
+
+    it("should create a post", async () => {
+        const content = "This is a test post.";
+
+        await socialMediaInstance.createPost(content);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.content, content, "Post content does not match");
+    });
+
+    it("should like a post", async () => {
+        const content = "This is another test post.";
+        await socialMediaInstance.createPost(content);
+
+        await socialMediaInstance.likeTweet(accounts[0], 0);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.likes, 1, "Post should have 1 like");
+    });
+
+    it("should unlike a post", async () => {
+        const content = "Yet another test post.";
+        await socialMediaInstance.createPost(content);
+
+        await socialMediaInstance.likeTweet(accounts[0], 0);
+        await socialMediaInstance.unlikeTweet(accounts[0], 0);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.likes, 0, "Post should have 0 likes");
+    });
+
+    it("should change post length", async () => {
+        const newPostLength = 300;
+
+        await socialMediaInstance.changePostLength(newPostLength);
+
+        const updatedPostLength = await socialMediaInstance.MAX_POST_LENGHT();
+        assert.equal(updatedPostLength, newPostLength, "Post length should be updated");
+    });
+});

web3_social_media/test/socialMedia.test.js

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+const SocialMedia = artifacts.require("SocialMedia");
+
+contract("SocialMedia", (accounts) => {
+    let socialMediaInstance;
+
+    beforeEach(async () => {
+        socialMediaInstance = await SocialMedia.new();
+    });
+
+    it("should create a post", async () => {
+        const content = "This is a test post.";
+
+        await socialMediaInstance.createPost(content);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.content, content, "Post content does not match");
+    });
+
+    it("should like a post", async () => {
+        const content = "This is another test post.";
+        await socialMediaInstance.createPost(content);
+
+        await socialMediaInstance.likeTweet(accounts[0], 0);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.likes, 1, "Post should have 1 like");
+    });
+
+    it("should unlike a post", async () => {
+        const content = "Yet another test post.";
+        await socialMediaInstance.createPost(content);
+
+        await socialMediaInstance.likeTweet(accounts[0], 0);
+        await socialMediaInstance.unlikeTweet(accounts[0], 0);
+
+        const post = await socialMediaInstance.getPost(0);
+        assert.equal(post.likes, 0, "Post should have 0 likes");
+    });
+
+    it("should change post length", async () => {
+        const newPostLength = 300;
+
+        await socialMediaInstance.changePostLength(newPostLength);
+
+        const updatedPostLength = await socialMediaInstance.MAX_POST_LENGHT();
+        assert.equal(updatedPostLength, newPostLength, "Post length should be updated");
+    });
+});