feat: diff between two verified Solidity contracts (#125)

Author: naddison36

README.md

@@ -49,6 +49,7 @@ The three subcommands:
 * class:    Generates a UML class diagram from Solidity source code. default
 * storage:  Generates a diagram of a contract's storage slots.
 * flatten:  Merges verified source files from a Blockchain explorer into one local file.
+* diff:     Compares the flattened Solidity code from a Blockchain explorer for two contracts.
 
 The Solidity code can be pulled from verified source code on Blockchain explorers like Etherscan or from local Solidity files.
 
@@ -73,7 +74,7 @@ Commands:
 ### Class usage
 
 ```
-Usage: sol2uml class <fileFolderAddress> [options]
+Usage: sol2uml class [options] <fileFolderAddress>
 
 Generates UML diagrams from Solidity source code.
 
@@ -114,7 +115,7 @@ Options:
 ### Storage usage
 
 ```
-Usage: sol2uml storage <fileFolderAddress> [options]
+Usage: sol2uml storage [options] <fileFolderAddress>
 
 WARNING: sol2uml does not use the Solidity compiler so may differ with solc. A known example is fixed-sized arrays declared with an expression will fail to be sized.
 
@@ -136,7 +137,7 @@ Options:
 ### Flatten usage
 
 ```
-Usage: sol2uml flatten <contractAddress> [options]
+Usage: sol2uml flatten <contractAddress>
 
 In order for the merged code to compile, the following is done:
 1. pragma solidity is set using the compiler of the verified contract.
@@ -154,6 +155,28 @@ Options:
   -h, --help       display help for command
 ```
 
+### Diff usage
+
+```
+Usage: sol2uml diff [options] <addressA> <addressB>
+
+The results show the comparision of contract A to B.
+The green sections are additions to contract B that are not in contract A.
+The red sections are removals from contract A that are not in contract B.
+The line numbers are from contract B. There are no line numbers for the red sections as they are not in contract B.
+
+Compare verified Solidity code differences between two contracts.
+
+Arguments:
+  addressA                  Contract address in hexadecimal format with a 0x prefix.
+  addressB                  Contract address in hexadecimal format with a 0x prefix.
+
+Options:
+  -l, --lineBuffer <value>  Minimum number a lines before and after changes (default: "4")
+  -s, --saveFiles           Save the flattened contract code to the filesystem. The file names will be the contract address with a .sol extension. (default: false)
+  -h, --help                display help for command
+```
+
 ## UML Class diagram examples
 
 To generate a diagram of all contracts under the contracts folder and its sub folders

jest.config.js

@@ -1,30 +1,11 @@
 // jest.config.js
 module.exports = {
-  verbose: true,
-  transform: {
-    "^.+\\.tsx?$": 'ts-jest'
-  },
-  testPathIgnorePatterns: [
-    "/build/",
-    "/node_modules/",
-  ],
-  testRegex: '/__tests__/.*\\.test\\.ts$',
-  moduleFileExtensions: [
-    'ts',
-    'tsx',
-    'js',
-    'jsx',
-    'json',
-    'node'
-  ],
-  globals: {
-    'ts-jest': {
-      diagnostics: {
-        // Do not fail on TS compilation errors
-        // https://kulshekhar.github.io/ts-jest/user/config/diagnostics#do-not-fail-on-first-error
-        warnOnly: true
-      }
-    }
-  },
-  testEnvironment: 'node'
+    verbose: true,
+    transform: {
+        '^.+\\.tsx?$': 'ts-jest',
+    },
+    testPathIgnorePatterns: ['/build/', '/node_modules/'],
+    testRegex: '/__tests__/.*\\.test\\.ts$',
+    moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
+    testEnvironment: 'node',
 }

lib/diff.d.ts

@@ -0,0 +1,7 @@
+/**
+ * Compares code using Google's diff_match_patch and displays the results in the console.
+ * @param codeA
+ * @param codeB
+ * @param lineBuff the number of lines to display before and after each change.
+ */
+export declare const diffCode: (codeA: string, codeB: string, lineBuff: number) => void;