Adding edit tool basically cloned from opencode

CMakeLists.txt

@@ -14,6 +14,7 @@ add_library(drharness_lib
     src/harness.cpp
     tools/shell_tool.cpp
     tools/agent_tool.cpp
+    tools/edit_tool.cpp
 )
 target_include_directories(drharness_lib PUBLIC include tools)
 target_link_libraries(drharness_lib

src/main.cpp

@@ -4,6 +4,7 @@
 #include "agent_profile.hpp"
 #include "shell_tool.hpp"
 #include "agent_tool.hpp"
+#include "edit_tool.hpp"
 #include <cstdlib>
 #include <iostream>
 #include <fstream>
@@ -24,6 +25,7 @@ static const std::vector<AgentProfile> profiles = {
 static const std::vector<std::string> default_tools =
 {
     "run_shell",
+    "edit",
 };
 
 
@@ -36,6 +38,7 @@ int main(int argc, char** argv) {
     ToolRegistry master_registery;
     ToolRegistry agent_tools;
     master_registery.register_tool(make_shell_tool());
+    master_registery.register_tool(make_edit_tool());
     // Add more base tools here:
     // registry.register_tool(make_file_read_tool());
 

tools/edit_tool.cpp

@@ -0,0 +1,95 @@
+#include "edit_tool.hpp"
+#include <fstream>
+#include <sstream>
+
+
+static int countOccurrences(const std::string& text, const std::string& target) {
+    int count = 0;
+    size_t pos = text.find(target);
+
+    while (pos != std::string::npos) {
+        ++count;
+        pos = text.find(target, pos + target.length());
+    }
+
+    return count;
+}
+
+Tool make_edit_tool() {
+    return Tool{
+        .name        = "edit",
+        .description = ""
+    "Performs exact string replacements in files.\n"
+    "\n"
+    "Usage:\n"
+    "- When editing text from Read tool output, ensure you preserve the exact indentation (tabs/spaces) as it appears AFTER the line number prefix. The line number prefix format is: line number + colon + space (e.g., `1: `). Everything after that space is the actual file content to match. Never include any part of the line number prefix in the oldString or newString.\n"
+//    "- ALWAYS prefer editing existing files in the codebase. NEVER write new files unless explicitly required.\n"
+    "- Only use emojis if the user explicitly requests it. Avoid adding emojis to files unless asked.\n"
+    "- The edit will FAIL if `oldString` is not found in the file with an error \"oldString not found in content\".\n"
+    "- The edit will FAIL if `oldString` is found multiple times in the file with an error \"Found multiple matches for oldString. Provide more surrounding lines in oldString to identify the correct match.\"",// Either provide a larger string with more surrounding context to make it unique or use `replaceAll` to change every instance of `oldString`. \n"
+//    "- Use `replaceAll` for replacing and renaming strings across the file. This parameter is useful if you want to rename a variable for instance.",
+
+        .parameters_schema = {
+            {"type", "object"},
+            {"properties", {
+                {"filePath", {
+                    {"type", "string"},
+                    {"description", "The absolute path to the file to modify"}
+                }},
+                {"oldString", {
+                    {"type", "string"},
+                    {"description", "The text to replace"}
+                }},
+                {"newString", {
+                    {"type", "string"},
+                    {"description", "The text to replace it with (must be different from oldString)"}
+                }},
+#if 0
+                {"replaceAll", {
+                    {"type", "bool"},
+                    {"description", "Replace all occurrences of oldString (default false)"}
+                }},
+#endif
+            }},
+            {"required", {"filePath", "oldString", "newString"}}
+        },
+        .execute = [](const nlohmann::json& args) -> std::string {
+            if (!args.contains("filePath") || !args["filePath"].is_string())
+                return "Error: missing required parameter 'filePath'";
+
+            if (!args.contains("oldString") || !args["oldString"].is_string())
+                return "Error: missing required parameter 'oldString'";
+
+            if (!args.contains("newString") || !args["newString"].is_string())
+                return "Error: missing required parameter 'newString'";
+
+            std::string oldString = args["oldString"];
+
+            std::ifstream in(args["filePath"]);
+
+            if (!in)
+                return "Error: Could not open file '" + std::string(args["filePath"]) + "'";
+
+            std::ostringstream sstr;
+            sstr << in.rdbuf();
+            std::string file_string = sstr.str(); // Contents of the file
+
+            auto count = countOccurrences(file_string, oldString);
+            if (count == 0)
+                return "Error: oldString not found in content";
+
+            if (count > 1)
+                return "Error: Found multiple matches for oldString. Provide more surrounding lines in oldString to identify the correct match.";
+
+            file_string = file_string.replace(
+                    file_string.find(oldString),
+                    oldString.length(),
+                    (std::string)args["newString"]);
+
+            std::ofstream output(args["filePath"]);
+            output << file_string;
+
+            return "Successfully edited file";
+        }
+    };
+}

tools/edit_tool.hpp

@@ -0,0 +1,4 @@
+#pragma once
+#include "tool.hpp"
+
+Tool make_edit_tool();