From 9730459fa21b22e275b9fb26bcd42461d4e84bf9 Mon Sep 17 00:00:00 2001
From: tintinweb <tintinweb@oststrom.com>
Date: Tue, 23 Nov 2021 19:19:56 +0100
Subject: [PATCH] add duperfinder

---
 src/rules/dupefinder.js | 58 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/rules/dupefinder.js

diff --git a/src/rules/dupefinder.js b/src/rules/dupefinder.js
new file mode 100644
index 0000000..653b6a6
--- /dev/null
+++ b/src/rules/dupefinder.js
@@ -0,0 +1,58 @@
+/**
+ * @author github.com/tintinweb
+ * @license MIT
+ * */
+
+const { BaseRule } = require("./builtin");
+const utils = require('../utils');
+const {AstHashedContractSync, HASH_MODES} = require("solidity-doppelganger");
+
+//["AST_EXACT", "AST_STRUCTURE"];
+
+class DupeFinder extends BaseRule {
+    constructor(solgrep, selectedModes) {
+        super(solgrep);
+        this.selectedModes = selectedModes || HASH_MODES;
+        this.dupeDb = {}; // {hash: [file, file, ...]}
+        this.selectedModes.forEach(mode => this.dupeDb[mode] = {});
+    }
+
+    onProcess(sourceUnit) {
+        Object.values(sourceUnit.contracts).forEach(contract => {
+            HASH_MODES.forEach(mode => {
+                let hashAst = new AstHashedContractSync({mode:mode}, sourceUnit.filePath).fromAst(contract.ast)
+                if(!this.dupeDb[mode][hashAst.hash] || !Array.isArray(this.dupeDb[mode][hashAst.hash])){
+                    this.dupeDb[mode][hashAst.hash] = [];
+                }
+                this.dupeDb[mode][hashAst.hash].push(`${sourceUnit.filePath}::${contract.name}`)
+            })
+            
+        });
+    }
+
+    onDirAnalyzed() {
+        this.solgrep.report(undefined, this, "DUPES", this.dupeDb);
+    }
+    onClose() {
+        var uniqueContracts = {};
+        
+        this.selectedModes.forEach(mode => {
+            if(typeof uniqueContracts[mode] === "undefined"){
+                uniqueContracts[mode] = 0;
+            }
+            uniqueContracts[mode] += Object.values(this.dupeDb[mode]).filter(v => v.length == 1).length; //number of contracts with unique hashes
+            this.dupeDb[mode] = utils.filterObjByValue(utils.sortObjByArrayLength(this.dupeDb[mode]), (v) => v.length > 1);
+        })
+        console.log("")
+        console.log("ℹ️  Duplicate Contracts (Hash => SourceUnits):")
+        console.log(this.dupeDb)
+        console.log("")
+        console.log("ℹ️  Number of Unique Contracts per matching method:")
+        console.log(uniqueContracts)
+    }
+}
+DupeFinder.description = "Find Duplicate Contracts! Either 'similar' (AST fuzzy matching) or exact (AST structure) matches.";
+
+module.exports = {
+    DupeFinder
+}
\ No newline at end of file