refactor: reduce unsafe 'as' type assertions throughout codebase

src/cli/commands/status.ts

@@ -37,9 +37,11 @@ export async function statusCommand(): Promise<void> {
           rule.frontmatter.targets[0] === "*" ? config.defaultTargets : rule.frontmatter.targets;
 
         for (const target of targets) {
-          if (target in targetCounts) {
-            targetCounts[target as keyof typeof targetCounts]++;
-          }
+          if (target === "copilot") targetCounts.copilot++;
+          else if (target === "cursor") targetCounts.cursor++;
+          else if (target === "cline") targetCounts.cline++;
+          else if (target === "claudecode") targetCounts.claudecode++;
+          else if (target === "roo") targetCounts.roo++;
         }
       }
 

src/core/mcp-parser.ts

@@ -1,6 +1,6 @@
 import * as fs from "node:fs";
 import * as path from "node:path";
-import type { RulesyncMcpConfig } from "../types/mcp.js";
+import type { RulesyncMcpConfig, RulesyncMcpServer } from "../types/mcp.js";
 
 export function parseMcpConfig(projectRoot: string): RulesyncMcpConfig | null {
   const mcpPath = path.join(projectRoot, ".rulesync", ".mcp.json");
@@ -11,7 +11,13 @@ export function parseMcpConfig(projectRoot: string): RulesyncMcpConfig | null {
 
   try {
     const content = fs.readFileSync(mcpPath, "utf-8");
-    const rawConfig = JSON.parse(content) as Record<string, unknown>;
+    const parsed = JSON.parse(content);
+
+    if (!parsed || typeof parsed !== "object") {
+      throw new Error("Invalid mcp.json: must be an object");
+    }
+
+    const rawConfig = parsed as Record<string, unknown>;
 
     // Handle legacy 'servers' field and migrate to 'mcpServers'
     if (rawConfig.servers && !rawConfig.mcpServers) {
@@ -28,7 +34,7 @@ export function parseMcpConfig(projectRoot: string): RulesyncMcpConfig | null {
       delete rawConfig.tools;
     }
 
-    return { mcpServers: rawConfig.mcpServers } as RulesyncMcpConfig;
+    return { mcpServers: rawConfig.mcpServers as Record<string, RulesyncMcpServer> };
   } catch (error) {
     throw new Error(
       `Failed to parse mcp.json: ${error instanceof Error ? error.message : String(error)}`,

src/core/parser.ts

@@ -47,6 +47,7 @@ export async function parseRuleFile(filepath: string): Promise<ParsedRule> {
   // Validate frontmatter
   validateFrontmatter(parsed.data, filepath);
 
+  // After validation, we can safely cast since validateFrontmatter ensures the shape
   const frontmatter = parsed.data as RuleFrontmatter;
   const filename = basename(filepath, ".md");
 

src/generators/mcp/claudecode.ts

@@ -77,7 +77,9 @@ export function generateClaudeMcpConfiguration(
 
     // Only add transport if it's supported by Claude
     if (transport && transport !== "stdio") {
-      claudeServer.transport = transport as "sse" | "http";
+      if (transport === "sse" || transport === "http") {
+        claudeServer.transport = transport;
+      }
     }
 
     settings.mcpServers![serverName] = claudeServer;

src/generators/mcp/cursor.ts

@@ -69,7 +69,7 @@ export function generateCursorMcpConfiguration(
       continue;
     }
 
-    // Cast to RulesyncMcpServer for type safety
+    // Cast to RulesyncMcpServer after type check
     const serverObj = server as RulesyncMcpServer;
 
     // Check if this server should be included for cursor

src/generators/mcp/roo.ts

@@ -86,7 +86,7 @@ export function generateRooMcpConfiguration(
       continue;
     }
 
-    // Cast to RulesyncMcpServer for type safety
+    // Cast to RulesyncMcpServer after type check
     const serverObj = server as RulesyncMcpServer;
 
     // Check if this server should be included for roo

src/parsers/claudecode.ts

@@ -160,9 +160,13 @@ async function parseClaudeSettings(settingsPath: string): Promise<ClaudeSettings
 
     // Extract ignore patterns from permissions.deny
     if (typeof settings === "object" && settings !== null && "permissions" in settings) {
-      const permissions = settings.permissions as Record<string, unknown>;
-      if (permissions && "deny" in permissions && Array.isArray(permissions.deny)) {
-        const readPatterns = permissions.deny
+      const permissions = settings.permissions;
+      if (typeof permissions !== "object" || permissions === null) {
+        return { errors };
+      }
+      const permsObj = permissions as Record<string, unknown>;
+      if (permsObj && "deny" in permsObj && Array.isArray(permsObj.deny)) {
+        const readPatterns = permsObj.deny
           .filter(
             (rule): rule is string =>
               typeof rule === "string" && rule.startsWith("Read(") && rule.endsWith(")"),

src/parsers/cursor.ts

@@ -33,11 +33,13 @@ const customMatterOptions = {
             // But exclude array literals (starting with [ or already quoted strings)
             .replace(/^(\s*globs:\s*)([^\s"'[\n][^"'[\n]*?)(\s*)$/gm, '$1"$2"$3');
 
-          return load(preprocessed, { schema: DEFAULT_SCHEMA }) as object;
+          const result = load(preprocessed, { schema: DEFAULT_SCHEMA });
+          return result as object;
         } catch (error) {
           // If that fails, try with FAILSAFE_SCHEMA as a fallback
           try {
-            return load(str, { schema: FAILSAFE_SCHEMA }) as object;
+            const result = load(str, { schema: FAILSAFE_SCHEMA });
+            return result as object;
           } catch {
             // If all else fails, throw the original error
             throw error;
@@ -56,6 +58,9 @@ function convertCursorMdcFrontmatter(
   _filename: string,
 ): RuleFrontmatter {
   // Type guard to ensure we have an object
+  if (!cursorFrontmatter || typeof cursorFrontmatter !== "object") {
+    throw new Error("Invalid frontmatter: expected object");
+  }
   const frontmatter = cursorFrontmatter as Record<string, unknown>;
 
   // Normalize values according to term definitions
@@ -274,7 +279,12 @@ export async function parseCursorConfiguration(
     try {
       const content = await readFileContent(cursorMcpPath);
       const mcp = JSON.parse(content);
-      if (mcp.mcpServers && Object.keys(mcp.mcpServers).length > 0) {
+      if (
+        mcp &&
+        typeof mcp === "object" &&
+        mcp.mcpServers &&
+        Object.keys(mcp.mcpServers).length > 0
+      ) {
         mcpServers = mcp.mcpServers as Record<string, RulesyncMcpServer>;
       }
     } catch (error) {

src/parsers/geminicli.ts

@@ -169,7 +169,12 @@ async function parseGeminiSettings(settingsPath: string): Promise<GeminiSettings
     const settings = JSON.parse(content);
 
     // Extract MCP servers
-    if (settings.mcpServers && Object.keys(settings.mcpServers).length > 0) {
+    if (
+      settings &&
+      typeof settings === "object" &&
+      settings.mcpServers &&
+      Object.keys(settings.mcpServers).length > 0
+    ) {
       mcpServers = settings.mcpServers as Record<string, RulesyncMcpServer>;
     }
   } catch (error) {