Turn on custom-error-definition and name the custom errors

scripts/project-lint.ts

@@ -260,9 +260,6 @@ const rules: DummyRuleMap = {
   // PENDING USER: union members are values in profiles.json, the Gitea API,
   // and posted comments; renaming them changes behavior.
   "explicit-types/upper-snake-string-unions": "off",
-  // PENDING USER: a fitting `name` needs a constructor and changes logged
-  // error names.
-  "unicorn/custom-error-definition": "off",
   // Off, too much churn:
   // Literal numbers read better than a constant per use.
   "no-magic-numbers": "off",

src/post/post.ts

@@ -36,7 +36,12 @@ const failureComment = (failures: ProfileFailure[]): string =>
 // The `fetch` subset the reviewer posts through, which tests replace.
 export type Fetcher = (url: string, init: RequestInit) => Promise<Response>;
 
-class GiteaRequestError extends Error {}
+class GiteaRequestError extends Error {
+  constructor(message: string, options?: ErrorOptions) {
+    super(message, options);
+    this.name = "GiteaRequestError";
+  }
+}
 
 function parseAnchors(text: string, sourcePath: string): Anchor[] {
   const entries: unknown = JSON.parse(text);

src/profiles/profiles.ts

@@ -29,7 +29,12 @@ interface ProfileHome {
 }
 
 // Raised once an agent's credentials are rejected and any re-login is spent.
-export class AgentAuthError extends Error {}
+export class AgentAuthError extends Error {
+  constructor(message: string, options?: ErrorOptions) {
+    super(message, options);
+    this.name = "AgentAuthError";
+  }
+}
 
 function isUsageExhausted(error: unknown): boolean {
   return /(?:usage|rate) limit|hit your (?:weekly )?limit|insufficient_quota|exceeded your current quota|too many requests|(?:api error|http error|http|status(?: code)?)[ :]+4(?:02|29)\b/iu.test(