feat(emdash-bot): maintainer-triggered investigation + fix-loop states (bot next-gen 2/5)

.oxfmtrc.json

@@ -9,6 +9,8 @@
 		"**/emdash-env.d.ts",
 		"**/worker-configuration.d.ts",
 		"packages/registry-lexicons/src/generated/**",
-		"packages/plugin-cli/schemas/**"
+		"packages/plugin-cli/schemas/**",
+		"infra/emdash-bot/.flue/lib/machine.json",
+		"infra/emdash-bot/BOT_STATE_MACHINE.md"
 	]
 }

infra/emdash-bot/.flue/agents/investigate.ts

@@ -37,7 +37,7 @@ const SANDBOX_EXEC_GRACE_MS = 30_000;
 const initialDataSchema = v.object({
 	runId: v.pipe(v.string(), v.minLength(1)),
 	issueNumber: v.number(),
-	mode: v.picklist(["repro", "implement", "revise"]),
+	mode: v.picklist(["repro", "implement", "revise", "diagnose", "fix"]),
 	arg: v.optional(v.nullable(v.string())),
 	issueTitle: v.pipe(v.string(), v.minLength(1)),
 	issueBody: v.string(),
@@ -173,12 +173,17 @@ async function setupSandbox(
 	if (!repo) throw new Error("repository context is not configured");
 	const cloneUrl = `https://github.com/${repo.owner}/${repo.repo}.git`;
 	const branch = input.mode === "revise" ? `bot/fix-${input.issueNumber}` : "main";
-	const pushCapability = await createPushCapability(
-		workerEnv.GITHUB_WEBHOOK_SECRET,
-		repo.owner,
-		repo.repo,
-		input.issueNumber,
-	);
+	// Diagnose mode is investigation-only: no push capability enters the
+	// sandbox, so a fix push is impossible rather than merely instructed against.
+	const pushCapability =
+		input.mode === "diagnose"
+			? null
+			: await createPushCapability(
+					workerEnv.GITHUB_WEBHOOK_SECRET,
+					repo.owner,
+					repo.repo,
+					input.issueNumber,
+				);
 	const steps: Array<{ name: string; command: string; timeoutMs?: number; nonFatal?: boolean }> = [
 		{
 			name: "git-identity-email",
@@ -200,10 +205,14 @@ async function setupSandbox(
 					name: "checkout-main",
 					command: `cd ${REPO_DIR} && git checkout main && git reset --hard origin/main`,
 				},
-		{
-			name: "git-push-capability",
-			command: `cd ${REPO_DIR} && git config http.https://github.com/.extraHeader '${PUSH_CAPABILITY_HEADER}: ${pushCapability}'`,
-		},
+		...(pushCapability
+			? [
+					{
+						name: "git-push-capability",
+						command: `cd ${REPO_DIR} && git config http.https://github.com/.extraHeader '${PUSH_CAPABILITY_HEADER}: ${pushCapability}'`,
+					},
+				]
+			: []),
 		{
 			name: "pnpm-install",
 			command: `cd ${REPO_DIR} && pnpm install --frozen-lockfile --prefer-offline`,
@@ -268,6 +277,22 @@ async function detectPush(issueNumber: number, previousBranchSha: string | null)
 
 function buildPrompt(input: InvestigateData): string {
 	const argSection = input.arg ? ["", "## Directive", "", input.arg, ""].join("\n") : "";
+	const diagnose = input.mode === "diagnose";
+	const method = diagnose
+		? [
+				"- Read AGENTS.md, find the relevant code, and attempt to reproduce the bug.",
+				"- Diagnose the root cause. Do NOT write or push a fix -- this is investigation only.",
+				"- Report `reproduced` and put the diagnosis in `summary`. Use verdict `unclear` only when you are blocked on information that only the reporter can supply.",
+			]
+		: [
+				"- Read AGENTS.md, find the relevant code, attempt to reproduce, build, or revise.",
+				"- Write tests where they make sense.",
+				"- Touch only files relevant to the issue. Do not bulk-format or modify .github/workflows.",
+				`- When done, commit and push: \`git checkout -B bot/fix-${input.issueNumber} && git add <files> && git commit -m '<message>' && git push -u origin HEAD --force-with-lease\`.`,
+			];
+	const closing = diagnose
+		? "Call report_result exactly once when finished. Do not set fixed; report reproduced and your verdict with the diagnosis in summary."
+		: "Call report_result exactly once when finished. fixed may only be true if a fix and test passed and the branch was pushed.";
 	return [
 		`Investigate issue #${input.issueNumber} in mode: ${input.mode}.`,
 		"",
@@ -279,11 +304,8 @@ function buildPrompt(input: InvestigateData): string {
 		argSection,
 		"## Method",
 		"",
-		"- Read AGENTS.md, find the relevant code, attempt to reproduce, build, or revise.",
-		"- Write tests where they make sense.",
-		"- Touch only files relevant to the issue. Do not bulk-format or modify .github/workflows.",
-		`- When done, commit and push: \`git checkout -B bot/fix-${input.issueNumber} && git add <files> && git commit -m '<message>' && git push -u origin HEAD --force-with-lease\`.`,
+		...method,
 		"",
-		"Call report_result exactly once when finished. fixed may only be true if a fix and test passed and the branch was pushed.",
+		closing,
 	].join("\n");
 }

infra/emdash-bot/.flue/lib/comments.ts

@@ -27,6 +27,20 @@ export function renderReadonlyReply(state: StateId | null): string {
 			return "I declined this. Reopen with `@emdashbot reopen` if circumstances change.";
 		case "failed":
 			return "My last attempt failed. A maintainer can `@emdashbot retry` or take it over.";
+		case "investigating":
+			return "Investigating now (reproduce + diagnose). I'll report a verdict with evidence.";
+		case "reproduced":
+			return "Reproduced it -- diagnosis in my last comment. A maintainer can `@emdashbot fix` to try a fix, or `@emdashbot decline`.";
+		case "not_reproduced":
+			return "I couldn't reproduce this; transcript above. Reply with steps that fail for you, or a maintainer can `@emdashbot decline`.";
+		case "needs_info":
+			return "I need more to go on -- see my last comment for what's missing.";
+		case "fixing":
+			return "Building a candidate fix.";
+		case "preview_building":
+			return "Building a preview so you can try the fix.";
+		case "awaiting_reporter":
+			return "Try the preview from my last comment. Reply `@emdashbot confirm` if it's fixed, or describe what's still wrong.";
 		default: {
 			const _exhaustive: never = state;
 			return `State: \`${String(_exhaustive)}\`.`;
@@ -52,6 +66,11 @@ export function renderAgentComment(
 
 	switch (decision.event) {
 		case "agent.fix_ready":
+			// The fix loop routes fix_ready into preview_building, where the preview
+			// pipeline posts a deployed-preview link on preview.ready; a pkg.pr.new
+			// install line is the legacy awaiting_feedback lane only.
+			if (decision.to === "preview_building")
+				return `${summary}\n\nBuilding a preview so you can try the change before I open a PR.`;
 			return [
 				summary,
 				"",
@@ -64,9 +83,13 @@ export function renderAgentComment(
 				"Reply `@emdashbot confirm` if it works and I'll open the PR, or `@emdashbot revise <feedback>` to push changes.",
 			].join("\n");
 		case "agent.reproduced":
+			if (decision.to === "reproduced")
+				return `${summary}\n\nA maintainer can \`@emdashbot fix\` to try a fix, or \`@emdashbot decline\`.`;
 			return `${summary}\n\nReply \`@emdashbot implement <directive>\` if you want me to take another swing with guidance.`;
 		case "agent.not_reproduced":
 			return `${summary}\n\nReply with steps that fail for you, or close if it's no longer relevant.`;
+		case "agent.needs_info":
+			return `${summary}\n\nReply with the details above; a maintainer can \`@emdashbot investigate\` again once they arrive.`;
 		default:
 			return summary;
 	}

infra/emdash-bot/.flue/lib/github.ts

@@ -183,6 +183,16 @@ export async function getBranchSha(
 	return json.commit?.sha ?? null;
 }
 
+/** Deletes a branch ref. A 404/422 means it is already gone, which is fine. */
+export async function deleteBranch(token: string, ctx: RepoContext, branch: string): Promise<void> {
+	const res = await githubFetch(
+		`${GITHUB_API}/repos/${ctx.owner}/${ctx.repo}/git/refs/heads/${encodeURIComponent(branch)}`,
+		{ method: "DELETE", headers: authHeaders(token) },
+	);
+	if (res.status === 404 || res.status === 422) return;
+	if (!res.ok) throw new Error(`deleteBranch(${branch}) failed: ${res.status} ${await res.text()}`);
+}
+
 export async function addLabels(
 	token: string,
 	ctx: RepoContext,
@@ -252,7 +262,7 @@ export async function getOpenPullRequest(
 export async function createPullRequest(
 	token: string,
 	ctx: RepoContext,
-	args: { headBranch: string; baseBranch: string; title: string; body: string },
+	args: { headBranch: string; baseBranch: string; title: string; body: string; draft?: boolean },
 ): Promise<CreatedPullRequest> {
 	const res = await githubFetch(`${GITHUB_API}/repos/${ctx.owner}/${ctx.repo}/pulls`, {
 		method: "POST",
@@ -262,6 +272,7 @@ export async function createPullRequest(
 			base: args.baseBranch,
 			title: args.title,
 			body: args.body,
+			draft: args.draft === true,
 		}),
 	});
 	if (!res.ok) {