Add language settings for AI-generated resume output (#252)

* Add language settings for AI-generated resume output

* Resolve merge conflicts for language settings PR

* Fix language settings review feedback and CI lint

* Tighten language setting precedence and onboarding validation

---------

Co-authored-by: saad <Saad>

shared/src/settings-registry.test.ts

@@ -118,6 +118,67 @@ describe("settingsRegistry helpers", () => {
     });
   });
 
+  describe("writing-style language settings", () => {
+    it("defaults to manual english", () => {
+      const previousLanguageMode = process.env.CHAT_STYLE_LANGUAGE_MODE;
+      const previousManualLanguage = process.env.CHAT_STYLE_MANUAL_LANGUAGE;
+
+      delete process.env.CHAT_STYLE_LANGUAGE_MODE;
+      delete process.env.CHAT_STYLE_MANUAL_LANGUAGE;
+
+      try {
+        expect(settingsRegistry.chatStyleLanguageMode.default()).toBe("manual");
+        expect(settingsRegistry.chatStyleManualLanguage.default()).toBe(
+          "english",
+        );
+      } finally {
+        if (previousLanguageMode === undefined) {
+          delete process.env.CHAT_STYLE_LANGUAGE_MODE;
+        } else {
+          process.env.CHAT_STYLE_LANGUAGE_MODE = previousLanguageMode;
+        }
+
+        if (previousManualLanguage === undefined) {
+          delete process.env.CHAT_STYLE_MANUAL_LANGUAGE;
+        } else {
+          process.env.CHAT_STYLE_MANUAL_LANGUAGE = previousManualLanguage;
+        }
+      }
+    });
+
+    it("parses and serializes supported language settings", () => {
+      expect(settingsRegistry.chatStyleLanguageMode.parse("manual")).toBe(
+        "manual",
+      );
+      expect(settingsRegistry.chatStyleLanguageMode.parse("match-resume")).toBe(
+        "match-resume",
+      );
+      expect(settingsRegistry.chatStyleLanguageMode.parse("auto")).toBeNull();
+      expect(settingsRegistry.chatStyleLanguageMode.parse("")).toBeNull();
+      expect(
+        settingsRegistry.chatStyleLanguageMode.serialize("match-resume"),
+      ).toBe("match-resume");
+      expect(settingsRegistry.chatStyleLanguageMode.serialize(null)).toBeNull();
+
+      expect(settingsRegistry.chatStyleManualLanguage.parse("english")).toBe(
+        "english",
+      );
+      expect(settingsRegistry.chatStyleManualLanguage.parse("german")).toBe(
+        "german",
+      );
+      expect(
+        settingsRegistry.chatStyleManualLanguage.parse("italian"),
+      ).toBeNull();
+      expect(settingsRegistry.chatStyleManualLanguage.parse("")).toBeNull();
+      expect(
+        settingsRegistry.chatStyleManualLanguage.serialize("spanish"),
+      ).toBe("spanish");
+      expect(
+        settingsRegistry.chatStyleManualLanguage.serialize(null),
+      ).toBeNull();
+    });
+  });
+
   describe("LLM provider parsing", () => {
     it("normalizes the documented openai-compatible alias", () => {
       expect(settingsRegistry.llmProvider.parse("openai-compatible")).toBe(

shared/src/settings-registry.ts

@@ -1,5 +1,11 @@
 import { z } from "zod";
-import type { ResumeProjectsSettings } from "./types/settings";
+import {
+  CHAT_STYLE_LANGUAGE_MODE_VALUES,
+  CHAT_STYLE_MANUAL_LANGUAGE_VALUES,
+  type ChatStyleLanguageMode,
+  type ChatStyleManualLanguage,
+  type ResumeProjectsSettings,
+} from "./types/settings";
 
 function parseNonEmptyStringOrNull(raw: string | undefined): string | null {
   return raw === undefined || raw === "" ? null : raw;
@@ -49,6 +55,25 @@ function serializeBitBool(value: boolean | null | undefined): string | null {
   return value ? "1" : "0";
 }
 
+function createEnumParser<const TValues extends readonly [string, ...string[]]>(
+  values: TValues,
+): (raw: string | undefined) => TValues[number] | null {
+  const allowedValues = new Set<string>(values);
+
+  return (raw: string | undefined): TValues[number] | null => {
+    if (!raw) return null;
+    return allowedValues.has(raw) ? (raw as TValues[number]) : null;
+  };
+}
+
+const parseChatStyleLanguageModeOrNull = createEnumParser(
+  CHAT_STYLE_LANGUAGE_MODE_VALUES,
+);
+
+const parseChatStyleManualLanguageOrNull = createEnumParser(
+  CHAT_STYLE_MANUAL_LANGUAGE_VALUES,
+);
+
 export const resumeProjectsSchema = z.object({
   maxProjects: z.number().int().min(0).max(100),
   lockedProjectIds: z.array(z.string().trim().min(1)).max(200),
@@ -307,6 +332,34 @@ export const settingsRegistry = {
     serialize: (value: string | null | undefined): string | null =>
       value ?? null,
   },
+  chatStyleLanguageMode: {
+    kind: "typed" as const,
+    schema: z.enum(CHAT_STYLE_LANGUAGE_MODE_VALUES),
+    default: (): ChatStyleLanguageMode =>
+      parseChatStyleLanguageModeOrNull(
+        typeof process !== "undefined"
+          ? process.env.CHAT_STYLE_LANGUAGE_MODE
+          : undefined,
+      ) ?? "manual",
+    parse: parseChatStyleLanguageModeOrNull,
+    serialize: (
+      value: ChatStyleLanguageMode | null | undefined,
+    ): string | null => value ?? null,
+  },
+  chatStyleManualLanguage: {
+    kind: "typed" as const,
+    schema: z.enum(CHAT_STYLE_MANUAL_LANGUAGE_VALUES),
+    default: (): ChatStyleManualLanguage =>
+      parseChatStyleManualLanguageOrNull(
+        typeof process !== "undefined"
+          ? process.env.CHAT_STYLE_MANUAL_LANGUAGE
+          : undefined,
+      ) ?? "english",
+    parse: parseChatStyleManualLanguageOrNull,
+    serialize: (
+      value: ChatStyleManualLanguage | null | undefined,
+    ): string | null => value ?? null,
+  },
   backupEnabled: {
     kind: "typed" as const,
     schema: z.boolean(),

shared/src/settings-schema.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, it } from "vitest";
+import { updateSettingsSchema } from "./settings-schema";
+
+describe("updateSettingsSchema language settings", () => {
+  it("accepts supported language mode and manual language values", () => {
+    expect(
+      updateSettingsSchema.parse({
+        chatStyleLanguageMode: "manual",
+        chatStyleManualLanguage: "german",
+      }),
+    ).toEqual({
+      chatStyleLanguageMode: "manual",
+      chatStyleManualLanguage: "german",
+    });
+
+    expect(
+      updateSettingsSchema.parse({
+        chatStyleLanguageMode: null,
+        chatStyleManualLanguage: null,
+      }),
+    ).toEqual({
+      chatStyleLanguageMode: null,
+      chatStyleManualLanguage: null,
+    });
+  });
+
+  it("rejects unsupported language mode and manual language values", () => {
+    const result = updateSettingsSchema.safeParse({
+      chatStyleLanguageMode: "auto",
+      chatStyleManualLanguage: "italian",
+    });
+
+    expect(result.success).toBe(false);
+
+    if (result.success) {
+      return;
+    }
+
+    expect(
+      result.error.flatten().fieldErrors.chatStyleLanguageMode,
+    ).toBeDefined();
+    expect(
+      result.error.flatten().fieldErrors.chatStyleManualLanguage,
+    ).toBeDefined();
+  });
+});

shared/src/testing/factories.ts

@@ -188,6 +188,16 @@ export const createAppSettings = (
   chatStyleFormality: { value: "medium", default: "medium", override: null },
   chatStyleConstraints: { value: "", default: "", override: null },
   chatStyleDoNotUse: { value: "", default: "", override: null },
+  chatStyleLanguageMode: {
+    value: "manual",
+    default: "manual",
+    override: null,
+  },
+  chatStyleManualLanguage: {
+    value: "english",
+    default: "english",
+    override: null,
+  },
   llmApiKeyHint: null,
   rxresumeApiKeyHint: null,
   rxresumeEmail: null,

shared/src/types/settings.ts

@@ -14,6 +14,34 @@ export interface ResumeProjectsSettings {
 
 export type RxResumeMode = "v4" | "v5";
 
+export const CHAT_STYLE_LANGUAGE_MODE_VALUES = [
+  "manual",
+  "match-resume",
+] as const;
+
+export type ChatStyleLanguageMode =
+  (typeof CHAT_STYLE_LANGUAGE_MODE_VALUES)[number];
+
+export const CHAT_STYLE_MANUAL_LANGUAGE_VALUES = [
+  "english",
+  "german",
+  "french",
+  "spanish",
+] as const;
+
+export type ChatStyleManualLanguage =
+  (typeof CHAT_STYLE_MANUAL_LANGUAGE_VALUES)[number];
+
+export const CHAT_STYLE_MANUAL_LANGUAGE_LABELS: Record<
+  ChatStyleManualLanguage,
+  string
+> = {
+  english: "English",
+  german: "German",
+  french: "French",
+  spanish: "Spanish",
+};
+
 export interface ResumeProfile {
   basics?: {
     name?: string;
@@ -135,6 +163,8 @@ export interface AppSettings {
   chatStyleFormality: Resolved<string>;
   chatStyleConstraints: Resolved<string>;
   chatStyleDoNotUse: Resolved<string>;
+  chatStyleLanguageMode: Resolved<ChatStyleLanguageMode>;
+  chatStyleManualLanguage: Resolved<ChatStyleManualLanguage>;
   backupEnabled: Resolved<boolean>;
   backupHour: Resolved<number>;
   backupMaxCount: Resolved<number>;