feat: add issue create and comment (task 0004)

Introduce the first mutations, along with the shared machinery the later
issue and PR mutation slices reuse.

- `issue create` with --title/--body/--body-file/--assignee/--label/
  --milestone/--fields, emitting `issue: { number, title, state, url }`
- `issue comment <n>`, echoing the created comment from the POST response
  with the body cleaned and truncated at 800 chars
- body-source resolution (--body vs --body-file), label and milestone
  name->ID lookup, repeatable flags, and the `joined`/`selectExtraFields`
  field extractors

Label lookup pages until exhausted, since a repo with more labels than one
page would otherwise fail to resolve a valid name. The end-to-end tier seeds
a mixed-case label and milestone and passes both in a different case, so the
case-insensitive lookup is verified against live Gitea rather than only
against fixtures.

src/commands/issue.ts

@@ -1,15 +1,25 @@
-import type { Comment, Issue } from "gitea-js";
+import type { Comment, CreateIssueOption, Issue } from "gitea-js";
 import {
   BODY_TRUNCATE_LIMIT,
   COMMENT_TRUNCATE_LIMIT,
   truncateBody,
 } from "../body.js";
+import { requireBodySource, resolveBodySource } from "../body-source.js";
 import { createClient } from "../client.js";
 import { resolveRepoContext, type RepoContext } from "../context.js";
 import type { CliDeps } from "../deps.js";
 import { axiError, classifyHttpError } from "../errors.js";
-import { extractRow, lowercased, pluck, relativeTimeField, type FieldDef } from "../fields.js";
-import { parseFlags } from "../flags.js";
+import {
+  extractRow,
+  joined,
+  lowercased,
+  pluck,
+  relativeTimeField,
+  selectExtraFields,
+  type FieldDef,
+} from "../fields.js";
+import { flagValue, parseFlags } from "../flags.js";
+import { resolveLabelIds, resolveMilestoneId } from "../lookup.js";
 import { formatCountLine, renderDetail, renderList, type DetailBlock } from "../render.js";
 import { relativeTime } from "../time.js";
 import { suggestCommand } from "../suggestions.js";
@@ -17,12 +27,49 @@ import { suggestCommand } from "../suggestions.js";
 export const ISSUE_HELP = `usage: gitea-axi issue <command> [flags]
 
 commands:
-  list    List issues in the current repository
-  view    Show a single issue's details
+  list       List issues in the current repository
+  view       Show a single issue's details
+  create     Create an issue
+  comment    Post a comment on an issue or pull request
 
 Run \`gitea-axi issue <command> --help\` for the flags of a command.
 `;
 
+export const ISSUE_CREATE_HELP = `usage: gitea-axi issue create --title <text> [flags]
+
+Create an issue in the current repository.
+
+flags:
+  --title <text>        Issue title (required)
+  --body <text>         Issue body
+  --body-file <path>    Read the issue body from a file (mutually exclusive with --body)
+  --assignee <login>    Assign the issue to a user
+  --label <name>        Apply a label by name (repeatable, case-insensitive)
+  --milestone <name>    Assign a milestone by name (case-insensitive)
+  --fields <a,b,c>      Append extra fields: labels, assignees, milestone, body
+  --help                Show this help
+
+global flags:
+  -R, --repo <OWNER/NAME>     Override the repository detected from the git origin remote
+  --login <name>              Select a tea login profile by name
+`;
+
+export const ISSUE_COMMENT_HELP = `usage: gitea-axi issue comment <number> [flags]
+
+Post a comment on an issue. Pull request numbers are accepted — issues and pull
+requests share the comment endpoint.
+
+flags:
+  --body <text>         Comment body (required unless --body-file is given)
+  --body-file <path>    Read the comment body from a file (mutually exclusive with --body)
+  --full                Echo the posted body in full, without truncating it at 800 chars
+  --help                Show this help
+
+global flags:
+  -R, --repo <OWNER/NAME>     Override the repository detected from the git origin remote
+  --login <name>              Select a tea login profile by name
+`;
+
 export const ISSUE_VIEW_HELP = `usage: gitea-axi issue view <number> [flags]
 
 Show a single issue. Pull request numbers are rejected — use \`pr view\` instead.
@@ -167,11 +214,8 @@ async function issueList(deps: CliDeps, args: string[]): Promise<string> {
   });
 }
 
-const ISSUE_VIEW_HELP_SUGGESTION = [
-  "Run `gitea-axi issue view --help` to see available flags",
-];
-
 function parseIssueNumber(positionals: string[], command: string): number {
+  const helpSuggestion = [`Run \`gitea-axi ${command} --help\` to see available flags`];
   if (positionals.length === 0) {
     throw axiError(`${command} requires an issue number`, "VALIDATION_ERROR", [
       `Run \`gitea-axi ${command} <number>\``,
@@ -181,7 +225,7 @@ function parseIssueNumber(positionals: string[], command: string): number {
     throw axiError(
       `Unexpected argument: ${positionals[1]}`,
       "VALIDATION_ERROR",
-      ISSUE_VIEW_HELP_SUGGESTION,
+      helpSuggestion,
     );
   }
   const raw = positionals[0]!;
@@ -190,7 +234,7 @@ function parseIssueNumber(positionals: string[], command: string): number {
     throw axiError(
       `Invalid issue number: ${raw} (expected a positive integer)`,
       "VALIDATION_ERROR",
-      ISSUE_VIEW_HELP_SUGGESTION,
+      helpSuggestion,
     );
   }
   return number;
@@ -313,6 +357,155 @@ async function issueView(deps: CliDeps, args: string[]): Promise<string> {
   });
 }
 
+const ISSUE_CREATE_HELP_SUGGESTION = [
+  "Run `gitea-axi issue create --help` to see available flags",
+];
+
+// Default create output, per the spec: number, title, state, url (= html_url).
+const ISSUE_CREATE_FIELDS: FieldDef<Issue>[] = [
+  pluck("number"),
+  pluck("title"),
+  lowercased("state"),
+  pluck("url", "html_url"),
+];
+
+// Appended to the defaults on request via `--fields`, never replacing them.
+const ISSUE_CREATE_EXTRA_FIELDS: Record<string, FieldDef<Issue>> = {
+  labels: joined("labels", "labels", "name"),
+  assignees: joined("assignees", "assignees", "login"),
+  milestone: pluck("milestone", "milestone.title"),
+  body: pluck("body"),
+};
+
+async function issueCreate(deps: CliDeps, args: string[]): Promise<string> {
+  if (args.includes("--help")) {
+    return ISSUE_CREATE_HELP;
+  }
+  const { flags, lists, positionals } = parseFlags(
+    args,
+    {
+      "--title": { takesValue: true },
+      "--body": { takesValue: true },
+      "--body-file": { takesValue: true },
+      "--assignee": { takesValue: true },
+      "--label": { takesValue: true, repeatable: true },
+      "--milestone": { takesValue: true },
+      "--fields": { takesValue: true },
+    },
+    "issue create",
+  );
+  if (positionals.length > 0) {
+    throw axiError(
+      `Unexpected argument: ${positionals[0]}`,
+      "VALIDATION_ERROR",
+      ISSUE_CREATE_HELP_SUGGESTION,
+    );
+  }
+
+  // Everything that can fail on the caller's own input is settled before any
+  // request goes out, so a rejected invocation never half-creates an issue.
+  const title = flagValue(flags, "--title");
+  if (title === undefined) {
+    throw axiError("issue create requires --title <text>", "VALIDATION_ERROR", [
+      "Run `gitea-axi issue create --title <text>`",
+    ]);
+  }
+  const body = resolveBodySource(deps, flags, "issue create");
+  const extraFields = selectExtraFields(
+    flagValue(flags, "--fields"),
+    ISSUE_CREATE_EXTRA_FIELDS,
+    "issue create",
+  );
+  const assignee = flagValue(flags, "--assignee");
+  const milestoneName = flagValue(flags, "--milestone");
+  const labelNames = lists["--label"] ?? [];
+
+  const context = await resolveRepoContext(deps);
+  const api = createClient(context);
+
+  const payload: CreateIssueOption = { title };
+  if (body !== undefined) {
+    payload.body = body;
+  }
+  if (assignee !== undefined) {
+    payload.assignees = [assignee];
+  }
+  const labelIds = await resolveLabelIds(api, context, labelNames);
+  if (labelIds.length > 0) {
+    payload.labels = labelIds;
+  }
+  if (milestoneName !== undefined) {
+    payload.milestone = await resolveMilestoneId(api, context, milestoneName);
+  }
+
+  let issue: Issue;
+  try {
+    const response = await api.repos.issueCreateIssue(context.owner, context.name, payload);
+    issue = response.data;
+  } catch (error) {
+    throw classifyHttpError(error);
+  }
+
+  const item = extractRow(issue, [...ISSUE_CREATE_FIELDS, ...extraFields], { now: new Date() });
+  return renderDetail({
+    noun: "issue",
+    item,
+    help: [
+      suggestCommand(context, `issue view ${issue.number}`, "to see the issue in full"),
+    ],
+  });
+}
+
+async function issueComment(deps: CliDeps, args: string[]): Promise<string> {
+  if (args.includes("--help")) {
+    return ISSUE_COMMENT_HELP;
+  }
+  const { flags, positionals } = parseFlags(
+    args,
+    {
+      "--body": { takesValue: true },
+      "--body-file": { takesValue: true },
+      "--full": { takesValue: false },
+    },
+    "issue comment",
+  );
+  const number = parseIssueNumber(positionals, "issue comment");
+  const body = requireBodySource(deps, flags, "issue comment");
+  const full = flags["--full"] === true;
+
+  // No type guard here: issues and pull requests genuinely share this endpoint,
+  // so a PR number is a valid target and is never fetched to be checked.
+  const context = await resolveRepoContext(deps);
+  const api = createClient(context);
+  let comment: Comment;
+  try {
+    const response = await api.repos.issueCreateComment(context.owner, context.name, number, {
+      body,
+    });
+    comment = response.data;
+  } catch (error) {
+    throw classifyHttpError(error);
+  }
+
+  const raw = comment.body ?? "";
+  const item = {
+    // The issue the comment was posted to — the comment's own id is not output.
+    number,
+    author: comment.user?.login ?? "",
+    created: relativeTime(comment.created_at, new Date()),
+    body: full ? raw : truncateBody(raw, COMMENT_TRUNCATE_LIMIT, context.host),
+  };
+
+  // Gitea marks a comment posted on a pull request with `pull_request_url`. Only
+  // an issue target gets the `issue view` suggestion: `issue view` type-guards
+  // pull requests, so suggesting it after commenting on one would hand back a
+  // command that is guaranteed to fail.
+  const help = comment.pull_request_url
+    ? [suggestCommand(context, "issue comment --help", "to see all issue comment flags")]
+    : [suggestCommand(context, `issue view ${number} --comments`, "to see the full thread")];
+  return renderDetail({ noun: "comment", item, help });
+}
+
 export function issueCommand(deps: CliDeps) {
   return async (args: string[]): Promise<string> => {
     const [subcommand, ...rest] = args;
@@ -325,6 +518,12 @@ export function issueCommand(deps: CliDeps) {
     if (subcommand === "view") {
       return issueView(deps, rest);
     }
+    if (subcommand === "create") {
+      return issueCreate(deps, rest);
+    }
+    if (subcommand === "comment") {
+      return issueComment(deps, rest);
+    }
     throw axiError(`Unknown issue command: ${subcommand}`, "VALIDATION_ERROR", [
       "Run `gitea-axi issue --help` to see available issue commands",
     ]);