pr-desc-cli/dist/commit-generator.js

AI-powered PR description generator

import { generateText } from "ai";
import { getAIModel } from "./models.js";
import { formatCommitMessage, ensureConventionalCommit } from "./utils.js";
export async function generateConventionalCommitMessage(changes, options) {
    const model = await getAIModel(options.provider, options.model);
    const maxFiles = options.maxFiles ?? 20;
    const maxDiffLines = options.maxDiffLines ?? 500;
    const fileSummaries = changes.files
        .slice(0, maxFiles)
        .map((f) => {
        const patch = f.patch
            ? f.patch.slice(0, maxDiffLines) +
                (f.patch.length > maxDiffLines ? "..." : "")
            : "";
        return `FILE: ${f.path} STATUS: ${f.status} +${f.additions} -${f.deletions}\n${patch}`;
    })
        .join("\n\n");
    function buildPrompt(changes, options, fileSummaries) {
        const gitDataSection = `
## Git Context
**Base Branch:** ${changes.baseBranch}  
**Current Branch:** ${changes.currentBranch}  
**Files Changed:** ${changes.files.length}  
**Insertions:** ${changes.stats.insertions}  
**Deletions:** ${changes.stats.deletions}  

### Recent Commits
${changes.commits
            .map((commit) => `- ${commit.message.trim()} (${commit.hash.slice(0, 7)})`)
            .join("\n")}

### File Changes (Summarized)
${fileSummaries}
`;
        const finalAiInstructionForCommit = `
Do *not* include any meta information or explanations — just the commit message
Do *not* include any labels like "Since I don't see the staged git diff, I'll provide a generic example based on common commit messages"
Do *not* include any labels like "Based on the staged git diff, I will generate a single Conventional Commit message." just the commit message
Do *not* include any labels like "Here's a suggested PR description", "Feel free to modify it"
Do *not* include any emojis.
Do *not* include any labels like "This is a suggested commit message" — just the commit message
Do *not* include any labels like "Unfortunately, I don't see any staged git diff output in your question. However, I can guide you on how to generate a Conventional Commit message based on common practices." just the commit message

Return *only* the commit line.
`;
        const basePrompt = `You are an expert software engineer. Based on the staged git diff, generate a SINGLE Conventional Commit message.
Rules:
- Use format: <type>(<optional scope>): <short imperative summary>
- type *must* be one of: feat, fix, docs, style, refactor, perf, test, chore, build, ci
- Summary *must* be <= 72 characters
- Do NOT include body or footer; ONLY the first line
- No trailing period
- Be precise and specific.
${options.typeHint ? `Preferred type (hint): ${options.typeHint}` : ""}`;
        return `
Git Changes: ${gitDataSection}
Base Prompt: ${basePrompt}
Final Instruction: ${finalAiInstructionForCommit}
`;
    }
    const prompt = buildPrompt(changes, options, fileSummaries);
    // refine
    if (options.refineFrom) {
        const prev = formatCommitMessage(options.refineFrom);
        const refinePrompt = `Previous commit suggestion: "${prev}"

Based on the staged git diff below, improve or correct the suggestion so it strictly follows Conventional Commits and accurately reflects the changes. Return ONLY the corrected commit line (no explanation):

<diff>
${fileSummaries}
</diff>

Rules:
- Use format: <type>(<optional scope>): <short imperative summary>
- type must be one of: feat, fix, docs, style, refactor, perf, test, chore, build, ci
- Summary must be <= 72 characters
- No trailing period
- Return only the first line (no body or footer)
${options.typeHint ? `Preferred type (hint): ${options.typeHint}` : ""}
`;
        try {
            const res = await generateText({
                model,
                prompt: refinePrompt,
                temperature: 0.15,
                maxTokens: 80,
            });
            const refinedRaw = res?.text ??
                res?.output?.[0]?.content ??
                res?.choices?.[0]?.text ??
                "";
            const cleaned = formatCommitMessage(refinedRaw || prev);
            return ensureConventionalCommit(cleaned, options.typeHint);
        }
        catch (err) {
            // just return the previous
            return ensureConventionalCommit(prev, options.typeHint);
        }
    }
    try {
        const res = await generateText({
            model,
            prompt,
            temperature: 0.3,
            maxTokens: 80,
        });
        const raw = res?.text ??
            res?.output?.[0]?.content ??
            res?.choices?.[0]?.text ??
            "";
        const cleaned = formatCommitMessage(raw);
        return ensureConventionalCommit(cleaned, options.typeHint);
    }
    catch (err) {
        throw err;
    }
}