refactor: standardize runtime guard patterns with lodash-es (#154)

* refactor(ui): replace runtime type guards with lodash-es predicates

* refactor(runtime): migrate typeof checks to lodash-es in core modules

* refactor(ipc): standardize runtime guards with lodash-es

* test(refactor): align runtime guard checks with lodash-es

* docs(agents): add lodash-es runtime guard skill summary

src/server/modules/proxy/clients/gemini.client.ts

@@ -1,6 +1,6 @@
 import { Injectable, Logger } from '@nestjs/common';
 import axios, { AxiosProxyConfig, AxiosRequestConfig, AxiosResponse } from 'axios';
-import { isNil } from 'lodash-es';
+import { isEmpty, isFunction, isNil, isObjectLike, isString } from 'lodash-es';
 import { GeminiRequest, GeminiResponse } from '../interfaces/request-interfaces';
 import { GeminiInternalRequest } from '../../../../lib/antigravity/types';
 import { getServerConfig } from '../../../server-config';
@@ -131,10 +131,10 @@ export class GeminiClient {
       extraHeaders,
     );
     const payload = response.data;
-    if (payload && typeof payload === 'object' && 'response' in payload) {
-      return payload.response;
+    if (isObjectLike(payload) && 'response' in payload) {
+      return (payload as { response: GeminiResponse }).response;
     }
-    return payload;
+    return payload as GeminiResponse;
   }
 
   private getInternalBaseUrls(): string[] {
@@ -255,7 +255,7 @@ export class GeminiClient {
       return fromObject;
     }
 
-    if (typeof responseData === 'string') {
+    if (isString(responseData)) {
       return this.extractAxiosErrorMessageFromText(responseData);
     }
 
@@ -272,20 +272,20 @@ export class GeminiClient {
   }
 
   private extractAxiosErrorMessageFromObject(responseData: unknown): string | null {
-    if (!responseData || typeof responseData !== 'object' || this.isReadableStream(responseData)) {
+    if (!isObjectLike(responseData) || this.isReadableStream(responseData)) {
       return null;
     }
 
     const errorRecord = (responseData as { error?: unknown }).error;
-    if (errorRecord && typeof errorRecord === 'object') {
+    if (isObjectLike(errorRecord)) {
       const message = (errorRecord as { message?: unknown }).message;
-      if (typeof message === 'string' && message.trim() !== '') {
+      if (isString(message) && !isEmpty(message.trim())) {
         return message.trim();
       }
     }
 
     const message = (responseData as { message?: unknown }).message;
-    if (typeof message === 'string' && message.trim() !== '') {
+    if (isString(message) && !isEmpty(message.trim())) {
       return message.trim();
     }
 
@@ -333,11 +333,7 @@ export class GeminiClient {
   }
 
   private isReadableStream(value: unknown): value is NodeJS.ReadableStream {
-    return (
-      Boolean(value) &&
-      typeof value === 'object' &&
-      typeof (value as { pipe?: unknown }).pipe === 'function'
-    );
+    return isObjectLike(value) && isFunction((value as { pipe?: unknown }).pipe);
   }
 
   private async readStreamAsText(stream: NodeJS.ReadableStream): Promise<string | null> {
@@ -407,17 +403,17 @@ export class GeminiClient {
   }
 
   private extractRetryAfterHeader(headers: unknown): string | undefined {
-    if (!headers || typeof headers !== 'object') {
+    if (!isObjectLike(headers)) {
       return undefined;
     }
 
     const retryAfter = (headers as Record<string, unknown>)['retry-after'];
-    if (typeof retryAfter === 'string' && retryAfter.trim() !== '') {
+    if (isString(retryAfter) && !isEmpty(retryAfter.trim())) {
       return retryAfter.trim();
     }
     if (Array.isArray(retryAfter) && retryAfter.length > 0) {
       const first = retryAfter[0];
-      if (typeof first === 'string' && first.trim() !== '') {
+      if (isString(first) && !isEmpty(first.trim())) {
         return first.trim();
       }
     }
@@ -439,7 +435,7 @@ export class GeminiClient {
     try {
       const seen = new WeakSet();
       return JSON.stringify(obj, (key, value) => {
-        if (typeof value === 'object' && value !== null) {
+        if (isObjectLike(value)) {
           if (seen.has(value)) return '[Circular]';
           seen.add(value);
         }

src/server/modules/proxy/clients/upstream-error.ts

@@ -1,3 +1,5 @@
+import { isNumber, isObjectLike, isString } from 'lodash-es';
+
 export interface UpstreamErrorHeaders {
   retryAfter?: string;
 }
@@ -16,10 +18,10 @@ export class UpstreamRequestError extends Error {
     super(params.message);
     this.name = 'UpstreamRequestError';
 
-    if (params.status && typeof params.status !== 'number') {
+    if (params.status && !isNumber(params.status)) {
       throw new TypeError('status must be a number');
     }
-    if (params.headers && typeof params.headers !== 'object') {
+    if (params.headers && !isObjectLike(params.headers)) {
       throw new TypeError('headers must be an object');
     }
 
@@ -27,7 +29,7 @@ export class UpstreamRequestError extends Error {
     this.headers = params.headers;
 
     // Sanitize and limit body size
-    if (typeof params.body === 'string') {
+    if (isString(params.body)) {
       const sanitized = params.body.replace(/<[^>]*>?/gm, '');
       this.body = sanitized.substring(0, 1000);
     } else {

src/server/modules/proxy/gemini.controller.ts

@@ -11,7 +11,7 @@ import {
   Optional,
 } from '@nestjs/common';
 import { FastifyReply } from 'fastify';
-import { isEmpty } from 'lodash-es';
+import { isEmpty, isFunction, isNumber, isString } from 'lodash-es';
 import { Observable } from 'rxjs';
 
 import { ProxyGuard } from './proxy.guard';
@@ -198,7 +198,7 @@ export class GeminiController {
     const candidates = (response.candidates ?? []).map((candidate, index) => ({
       content: candidate.content,
       finishReason: candidate.finishReason,
-      index: typeof candidate.index === 'number' ? candidate.index : index,
+      index: isNumber(candidate.index) ? candidate.index : index,
     }));
 
     const normalized: GeminiResponse = {
@@ -246,8 +246,8 @@ export class GeminiController {
   private writeObservableSseResponse(res: FastifyReply, stream: Observable<unknown>): void {
     if (
       !res.raw ||
-      typeof res.raw.writeHead !== 'function' ||
-      typeof res.raw.write !== 'function'
+      !isFunction(res.raw.writeHead) ||
+      !isFunction(res.raw.write)
     ) {
       res.header('Content-Type', 'text/event-stream');
       res.header('Cache-Control', 'no-cache');
@@ -271,7 +271,7 @@ export class GeminiController {
         if (res.raw.writableEnded) {
           return;
         }
-        const payload = typeof chunk === 'string' ? chunk : String(chunk ?? '');
+        const payload = isString(chunk) ? chunk : String(chunk ?? '');
         res.raw.write(payload);
       },
       error: (error) => {
@@ -302,6 +302,6 @@ export class GeminiController {
   }
 
   private supportsReplyHijack(reply: FastifyReply): reply is FastifyReply & { hijack: () => void } {
-    return typeof (reply as { hijack?: unknown }).hijack === 'function';
+    return isFunction((reply as { hijack?: unknown }).hijack);
   }
 }

src/server/modules/proxy/proxy.controller.ts

@@ -12,7 +12,7 @@ import {
   Optional,
 } from '@nestjs/common';
 import { FastifyReply, FastifyRequest } from 'fastify';
-import { isNil, isPlainObject, isString } from 'lodash-es';
+import { isEmpty, isFunction, isNil, isObjectLike, isPlainObject, isString } from 'lodash-es';
 import { ProxyService } from './proxy.service';
 import { Observable } from 'rxjs';
 import {
@@ -339,7 +339,7 @@ export class ProxyController {
   private toLegacyTextCompletionsResponse(response: OpenAIChatResponse): Record<string, unknown> {
     const choice = response.choices?.[0];
     const content = choice?.message?.content;
-    const text = typeof content === 'string' ? content : '';
+    const text = isString(content) ? content : '';
 
     return {
       id: response.id,
@@ -397,7 +397,7 @@ export class ProxyController {
     stream?: boolean;
   }): OpenAIChatRequest {
     const messages: OpenAIChatRequest['messages'] = [];
-    if (body.instructions && body.instructions.trim() !== '') {
+    if (isString(body.instructions) && !isEmpty(body.instructions.trim())) {
       messages.push({
         role: 'system',
         content: body.instructions,
@@ -484,7 +484,7 @@ export class ProxyController {
           continue;
         }
       }
-    } else if (typeof body.input === 'string') {
+    } else if (isString(body.input)) {
       messages.push({
         role: 'user',
         content: body.input,
@@ -716,18 +716,14 @@ export class ProxyController {
   }
 
   private isObservableLike(value: unknown): value is Observable<unknown> {
-    return (
-      Boolean(value) &&
-      typeof value === 'object' &&
-      typeof (value as { subscribe?: unknown }).subscribe === 'function'
-    );
+    return isObjectLike(value) && isFunction((value as { subscribe?: unknown }).subscribe);
   }
 
   private writeSseResponse(res: FastifyReply, stream: Observable<unknown>): void {
     if (
       !res.raw ||
-      typeof res.raw.writeHead !== 'function' ||
-      typeof res.raw.write !== 'function'
+      !isFunction(res.raw.writeHead) ||
+      !isFunction(res.raw.write)
     ) {
       res.header('Content-Type', 'text/event-stream');
       res.header('Cache-Control', 'no-cache');
@@ -736,7 +732,7 @@ export class ProxyController {
       return;
     }
 
-    if (typeof (res as { hijack?: () => void }).hijack === 'function') {
+    if (isFunction((res as { hijack?: () => void }).hijack)) {
       (res as { hijack: () => void }).hijack();
     }
 
@@ -751,7 +747,7 @@ export class ProxyController {
         if (res.raw.writableEnded) {
           return;
         }
-        const payload = typeof chunk === 'string' ? chunk : String(chunk ?? '');
+        const payload = isString(chunk) ? chunk : String(chunk ?? '');
         res.raw.write(payload);
       },
       error: (error) => {
@@ -804,7 +800,7 @@ export class ProxyController {
       }
 
       const content = result.choices?.[0]?.message?.content;
-      const image = this.extractInlineBase64Image(typeof content === 'string' ? content : '');
+      const image = this.extractInlineBase64Image(isString(content) ? content : '');
       if (!image) {
         this.logProxyEndpointError(
           '/v1/images/generations',
@@ -908,7 +904,7 @@ export class ProxyController {
 
     if (!userMessage) {
       parts.push({ text: fallbackPrompt || 'Please generate an image based on this request.' });
-    } else if (typeof userMessage.content === 'string') {
+    } else if (isString(userMessage.content)) {
       parts.push({
         text:
           userMessage.content ||
@@ -917,7 +913,7 @@ export class ProxyController {
       });
     } else {
       for (const block of userMessage.content) {
-        if (block.type === 'text' && typeof block.text === 'string' && block.text.trim() !== '') {
+        if (block.type === 'text' && isString(block.text) && !isEmpty(block.text.trim())) {
           textParts.push(block.text);
         }
         if (block.type === 'image_url') {
@@ -964,7 +960,7 @@ export class ProxyController {
 
   private hasMultipartBoundary(req: FastifyRequest): boolean {
     const contentType = req.headers['content-type'];
-    if (typeof contentType !== 'string') {
+    if (!isString(contentType)) {
       return false;
     }
 

src/server/modules/proxy/proxy.service.ts

@@ -1,5 +1,5 @@
 import { Injectable, Logger, Inject } from '@nestjs/common';
-import { isEmpty, isNil, isPlainObject, isString } from 'lodash-es';
+import { isEmpty, isNil, isNumber, isPlainObject, isString } from 'lodash-es';
 import { TokenManagerService } from './token-manager.service';
 import { GeminiClient } from './clients/gemini.client';
 import { v4 as uuidv4 } from 'uuid';
@@ -511,7 +511,7 @@ export class ProxyService {
   private getModelOutputCap(accountId: string, model: string): number {
     const normalizedModel = this.normalizeModelIdentifier(model);
     const dynamicCap = this.tokenManager.getModelOutputLimitForAccount(accountId, normalizedModel);
-    if (typeof dynamicCap === 'number' && Number.isFinite(dynamicCap) && dynamicCap > 0) {
+    if (isNumber(dynamicCap) && Number.isFinite(dynamicCap) && dynamicCap > 0) {
       return Math.floor(dynamicCap);
     }
     return getMaxOutputTokens(normalizedModel);
@@ -523,7 +523,7 @@ export class ProxyService {
       accountId,
       normalizedModel,
     );
-    if (typeof dynamicBudget === 'number' && Number.isFinite(dynamicBudget) && dynamicBudget >= 0) {
+    if (isNumber(dynamicBudget) && Number.isFinite(dynamicBudget) && dynamicBudget >= 0) {
       return Math.floor(dynamicBudget);
     }
     return getThinkingBudget(normalizedModel);
@@ -548,12 +548,12 @@ export class ProxyService {
       | undefined;
     const adaptiveSentinel =
       thinkingConfig &&
-      (typeof thinkingConfig.thinkingLevel === 'string' ||
+      (isString(thinkingConfig.thinkingLevel) ||
         thinkingConfig.thinkingBudget === -1 ||
         thinkingConfig.thinkingBudget === 32768);
 
     if (thinkingConfig) {
-      if (!isClaudeModel && typeof thinkingConfig.thinkingLevel === 'string') {
+      if (!isClaudeModel && isString(thinkingConfig.thinkingLevel)) {
         const converted = this.resolveThinkingLevelBudget(thinkingConfig.thinkingLevel);
         if (converted !== undefined) {
           thinkingConfig.thinkingBudget = converted;
@@ -561,12 +561,12 @@ export class ProxyService {
         delete thinkingConfig.thinkingLevel;
       }
 
-      if (typeof thinkingConfig.thinkingBudget === 'number' && thinkingConfig.thinkingBudget < 0) {
+      if (isNumber(thinkingConfig.thinkingBudget) && thinkingConfig.thinkingBudget < 0) {
         thinkingConfig.thinkingBudget = Math.min(thinkingBudgetCap, 24576);
       }
 
       if (
-        typeof thinkingConfig.thinkingBudget === 'number' &&
+        isNumber(thinkingConfig.thinkingBudget) &&
         Number.isFinite(thinkingConfig.thinkingBudget)
       ) {
         thinkingConfig.thinkingBudget = Math.min(
@@ -595,7 +595,7 @@ export class ProxyService {
     }
 
     if (
-      typeof generationConfig.maxOutputTokens === 'number' &&
+      isNumber(generationConfig.maxOutputTokens) &&
       Number.isFinite(generationConfig.maxOutputTokens)
     ) {
       generationConfig.maxOutputTokens = Math.min(
@@ -634,7 +634,7 @@ export class ProxyService {
       ? response.candidates.map((candidate, index) => ({
           content: candidate?.content,
           finishReason: candidate?.finishReason,
-          index: typeof candidate?.index === 'number' ? candidate.index : index,
+          index: isNumber(candidate?.index) ? candidate.index : index,
         }))
       : [];
 
@@ -1115,7 +1115,7 @@ export class ProxyService {
       const choice = response.choices?.[0];
       const finishReason = choice?.finish_reason ?? 'stop';
       const content =
-        choice?.message && typeof choice.message.content === 'string' ? choice.message.content : '';
+        choice?.message && isString(choice.message.content) ? choice.message.content : '';
       const chunkSize = 80;
 
       if (content.length === 0) {
@@ -1216,7 +1216,7 @@ export class ProxyService {
       systemInstruction: request.systemInstruction
         ? {
             parts: request.systemInstruction.parts
-              .filter((part): part is { text: string } => typeof part.text === 'string')
+              .filter((part): part is { text: string } => isString(part.text))
               .map((part) => ({ text: part.text })),
           }
         : undefined,
@@ -1294,7 +1294,7 @@ export class ProxyService {
   private convertOpenAIPartsToAnthropicContent(
     content: OpenAIChatRequest['messages'][number]['content'],
   ): AnthropicContent[] {
-    if (typeof content === 'string') {
+    if (isString(content)) {
       return content.trim() ? [{ type: 'text', text: content }] : [];
     }
 
@@ -1328,7 +1328,7 @@ export class ProxyService {
   private extractOpenAITextContent(
     content: OpenAIChatRequest['messages'][number]['content'],
   ): string {
-    if (typeof content === 'string') {
+    if (isString(content)) {
       return content;
     }
 
@@ -1339,14 +1339,14 @@ export class ProxyService {
   }
 
   private parseOpenAIFunctionArguments(argumentsString: string): Record<string, unknown> {
-    if (!argumentsString || argumentsString.trim() === '') {
+    if (isEmpty(argumentsString.trim())) {
       return {};
     }
 
     try {
       const parsed = JSON.parse(argumentsString);
-      if (this.isRecord(parsed)) {
-        return parsed;
+      if (isPlainObject(parsed)) {
+        return parsed as Record<string, unknown>;
       }
       return { value: parsed };
     } catch {
@@ -1446,7 +1446,7 @@ export class ProxyService {
   }
 
   private normalizeToolCallArguments(input: unknown): string {
-    if (typeof input === 'string') {
+    if (isString(input)) {
       return input;
     }
     if (isNil(input)) {
@@ -1730,7 +1730,7 @@ export class ProxyService {
     const metadata = request.metadata;
     const sessionCandidate =
       metadata?.session_id ?? metadata?.sessionId ?? metadata?.user_id ?? metadata?.userId;
-    if (!isString(sessionCandidate) || sessionCandidate.trim() === '') {
+    if (!isString(sessionCandidate) || isEmpty(sessionCandidate.trim())) {
       return undefined;
     }
     return `anthropic:${sessionCandidate.trim()}`;
@@ -1740,17 +1740,13 @@ export class ProxyService {
     const extra = request.extra;
     const sessionCandidate =
       extra?.session_id ?? extra?.sessionId ?? extra?.user_id ?? extra?.userId;
-    if (!isString(sessionCandidate) || sessionCandidate.trim() === '') {
+    if (!isString(sessionCandidate) || isEmpty(sessionCandidate.trim())) {
       return undefined;
     }
     return `openai:${sessionCandidate.trim()}`;
   }
 
-  private isRecord(value: unknown): value is Record<string, unknown> {
+  private isGeminiPart(value: unknown): value is InternalGeminiPart {
     return isPlainObject(value);
   }
-
-  private isGeminiPart(value: unknown): value is InternalGeminiPart {
-    return this.isRecord(value);
-  }
 }

src/server/modules/proxy/rate-limit-tracker.ts

@@ -1,3 +1,5 @@
+import { isEmpty, isNumber, isObjectLike, isString } from 'lodash-es';
+
 export enum RateLimitReason {
   QuotaExhausted = 'quota_exhausted',
   RateLimitExceeded = 'rate_limit_exceeded',
@@ -68,7 +70,7 @@ function tryParseGoogleErrorBody(body: string | undefined): ParsedGoogleErrorBod
 
   try {
     const parsed = JSON.parse(trimmed) as ParsedGoogleErrorBody;
-    if (!parsed || typeof parsed !== 'object') {
+    if (!isObjectLike(parsed)) {
       return null;
     }
     return parsed;
@@ -96,7 +98,7 @@ export class RateLimitTracker {
   private readonly failureCounts = new Map<string, FailureCountEntry>();
 
   private buildLockoutKey(accountId: string, model?: string): string {
-    if (model && model.trim() !== '') {
+    if (!isEmpty(model?.trim() ?? '')) {
       return `${accountId}:${model}`;
     }
     return accountId;
@@ -150,7 +152,7 @@ export class RateLimitTracker {
     model?: string,
   ): void {
     const retryAfterSec = Math.max(2, Math.ceil((resetTimeMs - Date.now()) / 1000));
-    const key = model && model.trim() !== '' ? this.buildLockoutKey(accountId, model) : accountId;
+    const key = !isEmpty(model?.trim() ?? '') ? this.buildLockoutKey(accountId, model) : accountId;
     this.lockoutByKey.set(key, {
       resetTimeMs,
       retryAfterSec,
@@ -240,7 +242,7 @@ export class RateLimitTracker {
     const parsedBody = tryParseGoogleErrorBody(body);
     const details = Array.isArray(parsedBody?.error?.details) ? parsedBody?.error?.details : [];
     for (const detail of details) {
-      if (typeof detail.reason !== 'string' || detail.reason.trim() === '') {
+      if (!isString(detail.reason) || isEmpty(detail.reason.trim())) {
         continue;
       }
       const mappedReason = mapGoogleReasonToTrackerReason(detail.reason);
@@ -354,7 +356,7 @@ export class RateLimitTracker {
     const parsedBody = tryParseGoogleErrorBody(body);
     const details = Array.isArray(parsedBody?.error?.details) ? parsedBody.error.details : [];
     for (const detail of details) {
-      if (typeof detail.retryDelay === 'string' && detail.retryDelay.trim() !== '') {
+      if (isString(detail.retryDelay) && !isEmpty(detail.retryDelay.trim())) {
         const parsedDelay = parseDurationToSeconds(detail.retryDelay);
         if (parsedDelay !== null) {
           return parsedDelay;
@@ -362,8 +364,8 @@ export class RateLimitTracker {
       }
 
       if (
-        typeof detail.metadata?.retryDelay === 'string' &&
-        detail.metadata.retryDelay.trim() !== ''
+        isString(detail.metadata?.retryDelay) &&
+        !isEmpty(detail.metadata.retryDelay.trim())
       ) {
         const parsedDelay = parseDurationToSeconds(detail.metadata.retryDelay);
         if (parsedDelay !== null) {
@@ -372,8 +374,8 @@ export class RateLimitTracker {
       }
 
       if (
-        typeof detail.metadata?.quotaResetDelay === 'string' &&
-        detail.metadata.quotaResetDelay.trim() !== ''
+        isString(detail.metadata?.quotaResetDelay) &&
+        !isEmpty(detail.metadata.quotaResetDelay.trim())
       ) {
         const parsedDelay = parseDurationToSeconds(detail.metadata.quotaResetDelay);
         if (parsedDelay !== null) {
@@ -383,7 +385,7 @@ export class RateLimitTracker {
     }
 
     const retryAfter = parsedBody?.error?.retry_after;
-    if (typeof retryAfter === 'number' && retryAfter > 0) {
+    if (isNumber(retryAfter) && retryAfter > 0) {
       return Math.ceil(retryAfter);
     }
 

src/server/modules/proxy/request-user-agent.ts

@@ -1,4 +1,5 @@
 import axios from 'axios';
+import { isString } from 'lodash-es';
 import { getAntigravityVersion } from '../../../utils/antigravityVersion';
 import { logger } from '../../../utils/logger';
 
@@ -20,7 +21,7 @@ let cachedUserAgentResolution: UserAgentResolution | null = null;
 let pendingUserAgentResolution: Promise<UserAgentResolution> | null = null;
 
 function normalizeNonEmptyString(value: string | null | undefined): string | null {
-  if (typeof value !== 'string') {
+  if (!isString(value)) {
     return null;
   }
 
@@ -125,7 +126,7 @@ async function fetchTextPayload(url: string): Promise<string | null> {
       },
     });
 
-    if (typeof response.data === 'string') {
+    if (isString(response.data)) {
       return response.data;
     }
 

src/server/modules/proxy/token-manager.service.ts

@@ -1,4 +1,5 @@
 import { Injectable, Logger, OnModuleInit } from '@nestjs/common';
+import { isEmpty, isNumber, isString } from 'lodash-es';
 import { CloudAccountRepo } from '../../../ipc/database/cloudHandler';
 import { CloudAccount, CloudQuotaData } from '../../../types/cloudAccount';
 import { GoogleAPIService } from '../../../services/GoogleAPIService';
@@ -36,7 +37,7 @@ interface GetNextTokenOptions {
 type TokenEntry = [string, TokenData];
 
 function normalizeProjectId(projectId: string | null | undefined): string | undefined {
-  if (typeof projectId !== 'string') {
+  if (!isString(projectId)) {
     return undefined;
   }
 
@@ -53,7 +54,7 @@ function normalizeProjectId(projectId: string | null | undefined): string | unde
 }
 
 function normalizeModelId(modelId: string | null | undefined): string | undefined {
-  if (typeof modelId !== 'string') {
+  if (!isString(modelId)) {
     return undefined;
   }
   const normalized = modelId.replace(/^models\//i, '').trim();
@@ -61,7 +62,7 @@ function normalizeModelId(modelId: string | null | undefined): string | undefine
 }
 
 function normalizeClientKey(clientKey: string | undefined): string | undefined {
-  if (typeof clientKey !== 'string') {
+  if (!isString(clientKey)) {
     return undefined;
   }
   const normalized = clientKey.trim().toLowerCase();
@@ -190,7 +191,7 @@ export class TokenManagerService implements OnModuleInit {
     const accountId = this.resolveAccountId(params.accountIdOrEmail) ?? params.accountIdOrEmail;
     const normalizedModel = normalizeModelId(params.model);
     const hasExplicitRetryWindow =
-      Boolean(params.retryAfter && params.retryAfter.trim() !== '') ||
+      Boolean(isString(params.retryAfter) && !isEmpty(params.retryAfter.trim())) ||
       Boolean(params.body && params.body.includes('quotaResetDelay'));
 
     if (!hasExplicitRetryWindow && (params.status ?? 0) === 429) {
@@ -215,7 +216,7 @@ export class TokenManagerService implements OnModuleInit {
         if (
           parsed.reason !== RateLimitReason.QuotaExhausted ||
           !parsed.model ||
-          parsed.model.trim() === ''
+          isEmpty(parsed.model.trim())
         ) {
           this.accountCooldowns.set(accountId, Date.now() + parsed.retryAfterSec * 1000);
         }
@@ -258,7 +259,7 @@ export class TokenManagerService implements OnModuleInit {
     if (
       parsed.reason !== RateLimitReason.QuotaExhausted ||
       !parsed.model ||
-      parsed.model.trim() === ''
+      isEmpty(parsed.model.trim())
     ) {
       this.accountCooldowns.set(accountId, Date.now() + parsed.retryAfterSec * 1000);
     }
@@ -661,14 +662,14 @@ export class TokenManagerService implements OnModuleInit {
 
       const limitCandidate = modelInfo.max_output_tokens ?? modelInfo.max_tokens;
       if (
-        typeof limitCandidate === 'number' &&
+        isNumber(limitCandidate) &&
         Number.isFinite(limitCandidate) &&
         limitCandidate > 0
       ) {
         modelLimits[normalizedModel] = Math.floor(limitCandidate);
       }
 
-      if (typeof modelInfo.resetTime === 'string' && modelInfo.resetTime.trim() !== '') {
+      if (isString(modelInfo.resetTime) && !isEmpty(modelInfo.resetTime.trim())) {
         modelResetTimes[normalizedModel] = modelInfo.resetTime;
       }
     }
@@ -692,7 +693,7 @@ export class TokenManagerService implements OnModuleInit {
   }
 
   private findEarliestQuotaResetTime(modelResetTimes: Record<string, string>): string | null {
-    const validTimes = Object.values(modelResetTimes).filter((value) => value.trim() !== '');
+    const validTimes = Object.values(modelResetTimes).filter((value) => !isEmpty(value.trim()));
     if (validTimes.length === 0) {
       return null;
     }
@@ -1084,7 +1085,7 @@ export class TokenManagerService implements OnModuleInit {
         continue;
       }
       const budget = modelInfo?.thinking_budget;
-      if (typeof budget === 'number' && Number.isFinite(budget) && budget >= 0) {
+      if (isNumber(budget) && Number.isFinite(budget) && budget >= 0) {
         return Math.floor(budget);
       }
     }