From 500d731062d913ab446e603c53f312423ae08cb9 Mon Sep 17 00:00:00 2001
From: Alexander Van de Kleut <54694031+avandekleut@users.noreply.github.com>
Date: Wed, 20 Aug 2025 15:27:15 -0400
Subject: [PATCH] add system prompt path injection

---
 action.yml   |  4 ++++
 package.json |  3 ++-
 src/main.ts  | 26 +++++++++++++++++++++++++-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/action.yml b/action.yml
index 976aed7..584c682 100644
--- a/action.yml
+++ b/action.yml
@@ -15,6 +15,10 @@ inputs:
     description: "Glob patterns to exclude files from the diff analysis"
     required: false
     default: ""
+  system_prompt_path:
+    description: "Path to a file in the repository containing additional system prompt instructions"
+    required: false
+    default: ""
 runs:
   using: "node16"
   main: "dist/index.js"
diff --git a/package.json b/package.json
index 5ec57c8..48684c2 100644
--- a/package.json
+++ b/package.json
@@ -24,5 +24,6 @@
     "@vercel/ncc": "^0.36.1",
     "prettier": "^2.8.6",
     "typescript": "^5.0.2"
-  }
+  },
+  "packageManager": "yarn@1.22.22+sha512.a6b2f7906b721bba3d67d4aff083df04dad64c399707841b7acf00f6b133b7ac24255f2652fa22ae3534329dc6180534e98d17432037ff6fd140556e2bb3137e"
 }
diff --git a/src/main.ts b/src/main.ts
index 13677ae..62bd183 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,4 +1,5 @@
 import { readFileSync } from "fs";
+import { existsSync } from "fs";
 import * as core from "@actions/core";
 import OpenAI from "openai";
 import { Octokit } from "@octokit/rest";
@@ -8,6 +9,7 @@ import minimatch from "minimatch";
 const GITHUB_TOKEN: string = core.getInput("GITHUB_TOKEN");
 const OPENAI_API_KEY: string = core.getInput("OPENAI_API_KEY");
 const OPENAI_API_MODEL: string = core.getInput("OPENAI_API_MODEL");
+const SYSTEM_PROMPT_PATH: string = core.getInput("system_prompt_path");
 
 const octokit = new Octokit({ auth: GITHUB_TOKEN });
 
@@ -56,6 +58,25 @@ async function getDiff(
   return response.data;
 }
 
+function readSystemPrompt(): string {
+  if (!SYSTEM_PROMPT_PATH) {
+    return "";
+  }
+
+  try {
+    if (existsSync(SYSTEM_PROMPT_PATH)) {
+      const systemPrompt = readFileSync(SYSTEM_PROMPT_PATH, "utf8");
+      return systemPrompt.trim();
+    } else {
+      console.warn(`System prompt file not found: ${SYSTEM_PROMPT_PATH}`);
+      return "";
+    }
+  } catch (error) {
+    console.error(`Error reading system prompt file ${SYSTEM_PROMPT_PATH}:`, error);
+    return "";
+  }
+}
+
 async function analyzeCode(
   parsedDiff: File[],
   prDetails: PRDetails
@@ -79,13 +100,16 @@ async function analyzeCode(
 }
 
 function createPrompt(file: File, chunk: Chunk, prDetails: PRDetails): string {
+  const systemPrompt = readSystemPrompt();
+  const additionalInstructions = systemPrompt ? `\n\nAdditional instructions from repository:\n${systemPrompt}\n` : "";
+
   return `Your task is to review pull requests. Instructions:
 - Provide the response in following JSON format:  {"reviews": [{"lineNumber":  <line_number>, "reviewComment": "<review comment>"}]}
 - Do not give positive comments or compliments.
 - Provide comments and suggestions ONLY if there is something to improve, otherwise "reviews" should be an empty array.
 - Write the comment in GitHub Markdown format.
 - Use the given description only for the overall context and only comment the code.
-- IMPORTANT: NEVER suggest adding comments to the code.
+- IMPORTANT: NEVER suggest adding comments to the code.${additionalInstructions}
 
 Review the following code diff in the file "${
     file.to