Agentic review

package.json

@@ -28,6 +28,8 @@
     "@actions/core": "^1.10.0",
     "@actions/github": "^5.1.1",
     "@dqbd/tiktoken": "^1.0.7",
+    "@langchain/core": "^0.3.19",
+    "@langchain/google-genai": "^0.1.4",
     "@octokit/action": "^6.0.4",
     "@octokit/plugin-retry": "^4.1.3",
     "@octokit/plugin-throttling": "^6.1.0",
@@ -38,7 +40,6 @@
     "p-retry": "^5.1.2"
   },
   "devDependencies": {
-    "@jest/globals": "^29.5.0",
     "@types/node": "^20.4.2",
     "@typescript-eslint/eslint-plugin": "^5.59.6",
     "@typescript-eslint/parser": "^5.59.6",
@@ -53,7 +54,7 @@
     "jest": "^27.2.5",
     "js-yaml": "^4.1.0",
     "prettier": "2.8.8",
-    "ts-jest": "^27.1.2",
-    "typescript": "^4.9.5"
+    "tsx": "^4.19.2",
+    "typescript": "^5.7.2"
   }
 }

src/bot.ts

@@ -1,70 +1,133 @@
-import './fetch-polyfill'
-
-import {info, error, setFailed, warning} from '@actions/core'
-import pRetry from 'p-retry'
-import {Options} from './options'
+import {info, warning, error} from '@actions/core'
 import {EragAPI} from './erag'
+import {type Options} from './options'
+import {ChatGoogleGenerativeAI} from '@langchain/google-genai'
+import {PromptTemplate} from '@langchain/core/prompts'
+import {StringOutputParser} from '@langchain/core/output_parsers'
+import {Finding, FileInfo, PRSummaryInput} from './types'
 
-export class Bot {
-  private readonly api: EragAPI | null = null
+const PR_SUMMARY_TEMPLATE = `You are a code review assistant. Analyze this pull request and provide a clear, concise summary. This summary will be provided as a comment on the pull request and also used for context during the code review.
 
-  private readonly options: Options
+Title: {title}
+Description: {description}
 
-  constructor(options: Options) {
-    this.options = options
-    if (process.env.ERAG_ACCESS_TOKEN) {
-      this.api = new EragAPI(options.eragBaseUrl, options.model, options.eragProjectName, process.env.ERAG_ACCESS_TOKEN)
-    } else {
-      const err = "Unable to initialize the ERAG API, 'ERAG_ACCESS_TOKEN' environment variable is not available"
-      throw new Error(err)
-    }
+Changes:
+{changes}
+
+Provide a summary covering:
+1. The main purpose of the changes
+2. Key components modified
+3. Notable implementation details
+4. Anything specific that the code reviewer should pay special attention to
+
+Keep the summary focused and technical. Don't include code snippets, pleasantries, or unnecessary text.`
+
+const REVIEW_TEMPLATE = `You are a code review assistant. Analyze the following changes and provide specific, actionable feedback.
+
+Title: {title}
+Description: {description}
+
+PR Summary:
+{summary}
+
+Changes to Review:
+{files}
+
+For each potential issue found, provide:
+1. A clear description of the concern. Don't include code snippets, only explain the issue and a potential solution in a few sentences.
+2. The specific file and location
+3. Any symbols (functions, classes, variables) that are relevant to the issue
+
+IMPORTANT: Your response MUST be a valid JSON array of findings, each with these fields:
+- description: string (clear explanation of the issue)
+- file: string (full file path as appears in the input)
+- lines?: { start: number, end: number } (location of the issue in the updated file)
+
+Example response format:
+[
+  {
+    "description": "The error handling could be improved by logging the error message.",
+    "file": "src/handler.ts",
+    "lines": { "start": 15, "end": 20 }
   }
+]
 
-  chat = async (message: string): Promise<string> => {
-    let res: string = ''
-    try {
-      res = await this.chat_(message)
-      return res
-    } catch (e: any) {
-      warning(`Failed to chat: ${e.message}, backtrace: ${e.stack}`)
-      return res
+If there are no issues found, return an empty array.
+
+Focus on:
+- Potential bugs, regressions
+- Maintainability issues
+- Performance issues
+- Simplification opportunities (less code lines the better)
+
+Keep suggestions specific and actionable. Don't include general comments about coding style unless they impact maintainability.`
+
+export class Bot {
+  private readonly api: EragAPI
+  private readonly gemini: ChatGoogleGenerativeAI
+
+  constructor(options: Options) {
+    // Initialize Gemini
+    if (!process.env.GOOGLE_API_KEY) {
+      throw new Error("Unable to initialize Gemini, 'GOOGLE_API_KEY' environment variable is not available")
+    }
+    if (!process.env.ERAG_ACCESS_TOKEN) {
+      throw new Error("Unable to initialize the ERAG API, 'ERAG_ACCESS_TOKEN' environment variable is not available")
     }
+
+    this.gemini = new ChatGoogleGenerativeAI({
+      modelName: 'gemini-1.5-flash-latest',
+      maxOutputTokens: 1000,
+      apiKey: process.env.GOOGLE_API_KEY,
+      temperature: 0.4
+    })
+
+    // Initialize ERAG
+    this.api = new EragAPI(options.eragBaseUrl, 'bedrock-claude3.5-sonnet', options.eragProjectName, process.env.ERAG_ACCESS_TOKEN)
   }
 
-  private readonly chat_ = async (message: string): Promise<string> => {
-    if (!message) {
-      return ''
-    }
+  async reviewBatch(summary: string, files: FileInfo[]): Promise<Finding[]> {
+    try {
+      const prompt = REVIEW_TEMPLATE.replace('{summary}', summary).replace(
+        '{files}',
+        files.map(file => `File: ${file.filename}\nPatch:\n${file.patch}`).join('\n---\n')
+      )
 
-    if (!this.api) {
-      setFailed('The ERAG API is not initialized')
-      return ''
+      const response = await this.api.sendMessage(prompt)
+      try {
+        // Extract JSON array from response using regex
+        const match = response.match(/\[.*\]/s)
+        if (!match) {
+          error(`No JSON array found in response: ${response}`)
+          throw new Error('No JSON array found in response')
+        }
+        return JSON.parse(match[0]) as Finding[]
+      } catch (parseError) {
+        error(`Failed to parse response as JSON: ${response}`)
+        throw new Error(`Invalid JSON response: ${parseError}`)
+      }
+    } catch (e) {
+      throw new Error(`Failed to review batch: ${e}`)
     }
+  }
 
-    const start = Date.now()
-    let response: string = ''
+  async summarizePR(input: PRSummaryInput): Promise<string> {
     try {
-      if (this.options.debug) {
-        info('::group::Sending message to erag')
-        info(`\n\n ${message}\n\n`)
-        info('::endgroup::')
-      }
+      // Create and run the chain
+      const prompt = PromptTemplate.fromTemplate(PR_SUMMARY_TEMPLATE)
+      const chain = prompt.pipe(this.gemini).pipe(new StringOutputParser())
 
-      response = await pRetry(() => this.api!.sendMessage(message), {
-        retries: this.options.eragRetries
+      const summary = await chain.invoke({
+        title: input.title,
+        description: input.description,
+        changes: input.changes.map(change => `File: ${change.filename}\nPatch:\n${change.patch}`).join('\n---\n')
       })
 
-      if (this.options.debug) {
-        info('::group::Received response from erag')
-        info(`\n\n ${response}\n\n`)
-        info('::endgroup::')
-      }
-    } catch (err: any) {
-      error(`Failed to send message to erag: ${err}`)
+      info(`Generated PR Summary: ${summary}`)
+      return summary
+    } catch (e: any) {
+      warning(`Failed to generate PR summary: ${e.message}, backtrace: ${e.stack}`)
+      throw e
     }
-    const end = Date.now()
-    info(`erag sendMessage (including retries) response time: ${end - start} ms`)
-
-    return response
   }
 }

src/main.ts

@@ -2,7 +2,7 @@ import {info, setFailed, warning} from '@actions/core'
 import {Bot} from './bot'
 import {Options} from './options'
 import {Prompts} from './prompts'
-import {codeReview} from './review'
+import {codeReview} from './review_old'
 import {handleReviewComment} from './review-comment'
 
 async function run(): Promise<void> {

src/prompts.ts

@@ -1,9 +1,7 @@
 import {type Inputs} from './inputs'
 
 export class Prompts {
-  systemMessage = `$system_message
-
-`
+  systemMessage = `$system_message\n`
 
   summarize = `
 Provide your final response in markdown with the following content:
@@ -307,38 +305,19 @@ $comment
 \`\`\`
 `
 
-  renderSummarizeFileDiff(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.summarizeFileDiff
-    return inputs.render(prompt)
-  }
-
-  renderSummarizeChangesets(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.summarizeChangesets
-    return inputs.render(prompt)
-  }
-
-  renderSummarize(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.summarizePrefix + this.summarize
-    return inputs.render(prompt)
-  }
-
-  renderSummarizeShort(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.summarizePrefix + this.summarizeShort
-    return inputs.render(prompt)
-  }
-
-  renderSummarizeReleaseNotes(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.summarizePrefix + this.summarizeReleaseNotes
-    return inputs.render(prompt)
-  }
-
-  renderComment(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.comment
-    return inputs.render(prompt)
-  }
-
-  renderReviewFileDiff(inputs: Inputs): string {
-    const prompt = this.systemMessage + this.reviewFileDiff
-    return inputs.render(prompt)
-  }
+  renderComment = (inputs: Inputs) => `
+You are a code review assistant. Continue this code review discussion thread.
+
+Context:
+${inputs.diff}
+
+Previous comments:
+${inputs.commentChain}
+
+Latest comment:
+${inputs.comment}
+
+Provide a helpful, technical response that moves the discussion forward. If the discussion seems resolved, say so.
+If you need more context, mention specific files or symbols that would help you understand better.
+`
 }