feat: Add line-specific comments functionality

config.json

@@ -1 +1 @@
-{"promptStrategy":"modified-files"}
+{"promptStrategy":"line-comments"}

package.json

@@ -20,7 +20,8 @@
     "@anthropic-ai/sdk": "^0.36.3",
     "dotenv": "^16.4.7",
     "handlebars": "^4.7.8",
-    "probot": "^13.4.3"
+    "probot": "^13.4.3",
+    "zod": "^3.24.3"
   },
   "devDependencies": {
     "@types/node": "22.13.1",

src/anthropic-senders/default-sender.ts

@@ -0,0 +1,35 @@
+import Anthropic from '@anthropic-ai/sdk'
+
+/**
+ * Default Anthropic sender.
+ * This sender is used by default and sends the prompt to Anthropic
+ * expecting a regular text response.
+ *
+ * @param prompt - The prompt to send to Anthropic
+ * @returns The text response from Anthropic
+ */
+export async function defaultSender(prompt: string): Promise<string> {
+  // Initialize Anthropic client
+  const anthropic = new Anthropic({
+    apiKey: process.env.ANTHROPIC_API_KEY
+  })
+
+  // Send to Anthropic API
+  const message = await anthropic.messages.create({
+    model: 'claude-3-7-sonnet-latest',
+    max_tokens: 4096,
+    temperature: 0, // Using 0 for consistent, deterministic code review feedback
+    messages: [
+      {
+        role: 'user',
+        content: prompt
+      }
+    ]
+  })
+
+  // Extract text from the content block
+  if (message.content[0].type !== 'text') {
+    throw new Error('Unexpected response type from Anthropic')
+  }
+  return message.content[0].text
+}

src/anthropic-senders/index.ts

@@ -0,0 +1,27 @@
+import { defaultSender } from './default-sender.ts'
+import { lineCommentsSender } from './line-comments-sender.ts'
+
+/**
+ * Type definition for all Anthropic senders
+ */
+export type AnthropicSender = (prompt: string) => Promise<string>
+
+/**
+ * Gets the appropriate sender based on the strategy name.
+ * This selects how to send and process the response to/from Anthropic API.
+ *
+ * @param strategyName - The name of the prompt strategy used
+ * @returns The appropriate sender function
+ */
+export function getSender(strategyName?: string): AnthropicSender {
+  switch (strategyName?.toLowerCase()) {
+    case 'line-comments':
+      return lineCommentsSender
+    case 'default':
+    case 'modified-files':
+    default:
+      return defaultSender
+  }
+}
+
+export { defaultSender, lineCommentsSender }

src/anthropic-senders/line-comments-sender.ts

@@ -0,0 +1,120 @@
+import Anthropic from '@anthropic-ai/sdk'
+
+// Type for code review response
+interface CodeReviewResponse {
+  summary: string
+  comments: Array<{
+    path: string
+    line: number
+    body: string
+    suggestion?: string
+  }>
+}
+
+/**
+ * Line comments Anthropic sender.
+ * This sender uses Anthropic's Tool Use / Function Calling capability
+ * to enforce a structured JSON response with specific line-based comments.
+ *
+ * @param prompt - The prompt to send to Anthropic
+ * @returns A stringified JSON response containing structured review comments
+ */
+export async function lineCommentsSender(prompt: string): Promise<string> {
+  // Initialize Anthropic client
+  const anthropic = new Anthropic({
+    apiKey: process.env.ANTHROPIC_API_KEY
+  })
+
+  // Send to Anthropic API with tool use configuration
+  const message = await anthropic.messages.create({
+    model: 'claude-3-7-sonnet-latest',
+    max_tokens: 4096,
+    temperature: 0,
+    messages: [
+      {
+        role: 'user',
+        content: prompt
+      }
+    ],
+    tools: [
+      {
+        name: 'provide_code_review',
+        description:
+          'Provide structured code review with line-specific comments',
+        input_schema: {
+          type: 'object',
+          properties: {
+            summary: {
+              type: 'string',
+              description: 'Overall summary of the PR'
+            },
+            comments: {
+              type: 'array',
+              items: {
+                type: 'object',
+                properties: {
+                  path: {
+                    type: 'string',
+                    description: 'File path relative to repository root'
+                  },
+                  line: {
+                    type: 'integer',
+                    description: 'Line number for the comment'
+                  },
+                  body: {
+                    type: 'string',
+                    description: 'Detailed comment about the issue'
+                  },
+                  suggestion: {
+                    type: 'string',
+                    description: 'Suggested code to fix the issue (optional)'
+                  }
+                },
+                required: ['path', 'line', 'body']
+              }
+            }
+          },
+          required: ['summary', 'comments']
+        }
+      }
+    ]
+  })
+
+  // Extract response from tool use
+  // Find content blocks that are tool_use type
+  for (const content of message.content) {
+    if (content.type === 'tool_use') {
+      if (content.name === 'provide_code_review' && content.input) {
+        // Return the structured response as a JSON string
+        return JSON.stringify(content.input as CodeReviewResponse)
+      } else {
+        console.log('Input:', content.input)
+        console.log('Tool name:', content.name)
+        throw new Error('Tool name or input incorect')
+      }
+    } else {
+      // Fallback if tool use failed or returned unexpected format
+      if (content.type === 'text') {
+        // Try to parse any JSON that might be in the response
+        try {
+          const text = content.text
+          const jsonMatch = text.match(/```json\s*([\s\S]*?)\s*```/)
+          if (jsonMatch && jsonMatch[1]) {
+            return jsonMatch[1].trim()
+          }
+          // If the whole response is potentially JSON
+          if (text.trim().startsWith('{') && text.trim().endsWith('}')) {
+            return text
+          }
+
+          // Just return the text as is
+          return text
+        } catch {
+          // Silent catch - continue to next content block or error
+        }
+      }
+    }
+  }
+
+  throw new Error('Unexpected response format from Anthropic')
+}

src/comment-handlers/global-comment-handler.ts

@@ -0,0 +1,71 @@
+import { type Context, ProbotOctokit } from 'probot'
+
+type ListCommentsResponse = Awaited<
+  ReturnType<ProbotOctokit['rest']['issues']['listComments']>
+>
+
+type SingleComment = ListCommentsResponse['data'][number]
+
+// Marker to identify our AI analysis comments
+const COMMENT_MARKER = '<!-- REVU-AI-ANALYSIS -->'
+
+/**
+ * Find existing AI analysis comment by looking for the unique marker
+ */
+async function findExistingAnalysisComment(context: Context, prNumber: number) {
+  const repo = context.repo()
+
+  // Get all comments on the PR
+  const { data: comments } = await context.octokit.issues.listComments({
+    ...repo,
+    issue_number: prNumber
+  })
+
+  // Find the comment with our marker
+  return comments.find((comment) => comment.body.includes(COMMENT_MARKER))
+}
+
+/**
+ * Handles the creation or update of a global comment containing the analysis.
+ * This is the original behavior of the application.
+ */
+export async function globalCommentHandler(
+  context: Context,
+  prNumber: number,
+  analysis: string
+) {
+  // Format the analysis with our marker
+  const formattedAnalysis = `${COMMENT_MARKER}\n\n${analysis}`
+
+  // Check if we already have an analysis comment
+  const existingComment = await findExistingAnalysisComment(context, prNumber)
+
+  await upsertComment(context, existingComment, formattedAnalysis, prNumber)
+}
+
+export async function upsertComment(
+  context: Context,
+  existingComment: SingleComment,
+  formattedAnalysis: string,
+  prNumber: number
+) {
+  const repo = context.repo()
+
+  if (existingComment) {
+    // Update the existing comment
+    await context.octokit.issues.updateComment({
+      ...repo,
+      comment_id: existingComment.id,
+      body: formattedAnalysis
+    })
+    return `Updated existing analysis comment on PR #${prNumber}`
+  } else {
+    // Post a new comment
+    await context.octokit.issues.createComment({
+      ...repo,
+      issue_number: prNumber,
+      body: formattedAnalysis
+    })
+    return `Created new analysis comment on PR #${prNumber}`
+  }
+}

src/comment-handlers/index.ts

@@ -0,0 +1,32 @@
+import { type Context } from 'probot'
+import { globalCommentHandler } from './global-comment-handler.ts'
+import { lineCommentsHandler } from './line-comments-handler.ts'
+
+/**
+ * Callback type for comment handlers
+ */
+export type CommentHandler = (
+  context: Context,
+  prNumber: number,
+  analysis: string
+) => Promise<string>
+
+/**
+ * Gets the appropriate comment handler based on the strategy name.
+ * This allows for different comment handling strategies based on the prompt strategy.
+ *
+ * @param strategyName - The name of the prompt strategy used
+ * @returns The appropriate comment handler function
+ */
+export function getCommentHandler(strategyName: string): CommentHandler {
+  switch (strategyName.toLowerCase()) {
+    case 'line-comments':
+      return lineCommentsHandler
+    case 'default':
+    case 'modified-files':
+    default:
+      return globalCommentHandler
+  }
+}
+
+export { globalCommentHandler, lineCommentsHandler }