import { promises as fs } from "node:fs";
import { homedir } from "node:os";
import { join } from "node:path";
import type { ICachePlugin, TokenCacheContext } from "@azure/msal-node";
const CACHE_PATH = join(homedir(), ".teams-mcp-token-cache.json");
/**
* Custom file-based cache plugin for MSAL Node
* Stores tokens (including refresh tokens) in a JSON file
*/
export const cachePlugin: ICachePlugin = {
async beforeCacheAccess(cacheContext: TokenCacheContext): Promise<void> {
try {
const data = await fs.readFile(CACHE_PATH, "utf8");
cacheContext.tokenCache.deserialize(data);
} catch (error) {
// File doesn't exist or is invalid - start with empty cache
if ((error as NodeJS.ErrnoException).code !== "ENOENT") {
console.error("Warning: Could not read token cache:", error);
}
}
},
async afterCacheAccess(cacheContext: TokenCacheContext): Promise<void> {
if (cacheContext.cacheHasChanged) {
try {
const data = cacheContext.tokenCache.serialize();
await fs.writeFile(CACHE_PATH, data, "utf8");
} catch (error) {
console.error("Warning: Could not write token cache:", error);
}
}
},
};
export { CACHE_PATH };
