fix(cap-discord): expand ~/ in tokenFile path before reading

packages/cap-discord/src/config.ts

@@ -17,6 +17,7 @@
 // a JSON blob) — config, not the secret. The secret stays on disk.
 
 import { readFileSync } from "node:fs";
+import { homedir } from "node:os";
 import { type Static, Type } from "typebox";
 import { Value } from "typebox/value";
 
@@ -98,17 +99,25 @@ export function readToken(
   tokenFile: string,
   read: (path: string) => string = (p) => readFileSync(p, "utf8"),
 ): string {
+  // Expand a leading ~/ so configs can use the ~-relative paths the schema
+  // documents ("Absolute (or ~-relative) path"). Node's fs does NOT expand ~/
+  // (only the shell does), so without this an unexpanded path throws ENOENT —
+  // and because pi's loader swallows extension-load errors, the discord
+  // capability would silently never load. Mirrors cap-flair / cap-observatory.
+  const resolvedPath = tokenFile.startsWith("~/")
+    ? `${homedir()}/${tokenFile.slice(2)}`
+    : tokenFile;
   let contents: string;
   try {
-    contents = read(tokenFile);
+    contents = read(resolvedPath);
   } catch (err) {
     // err.message from fs already contains only the path, not contents.
     const reason = err instanceof Error ? err.message : "read failed";
     throw new Error(`discord capability: cannot read token file: ${reason}`);
   }
   const token = contents.trim();
   if (token.length === 0) {
-    throw new Error(`discord capability: token file ${tokenFile} is empty.`);
+    throw new Error(`discord capability: token file ${resolvedPath} is empty.`);
   }
   return token;
 }

packages/cap-discord/test/config.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "bun:test";
 import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
-import { tmpdir } from "node:os";
+import { homedir, tmpdir } from "node:os";
 import { join } from "node:path";
 import { Value } from "typebox/value";
 import { CONFIG_ENV_VAR, CONFIG_SCHEMA, loadConfigFromEnv, readToken } from "../src/config.js";
@@ -99,6 +99,30 @@ describe("readToken", () => {
     expect(msg).not.toContain("the-secret-token");
   });
 
+  it("expands a leading ~/ in the token file path to the home dir", () => {
+    // Node's fs does NOT expand ~/ (only the shell does); readToken must, so a
+    // bob.yaml `tokenFile: ~/...` does not throw ENOENT and silently kill the
+    // cap. Use the read seam to capture the path actually opened — never a real
+    // token file.
+    let opened = "";
+    const token = readToken("~/agents/rivet/.pi-agent/discord.token", (p) => {
+      opened = p;
+      return "tok-from-home\n";
+    });
+    expect(opened).toBe(`${homedir()}/agents/rivet/.pi-agent/discord.token`);
+    expect(opened.startsWith("~/")).toBe(false);
+    expect(token).toBe("tok-from-home");
+  });
+
+  it("leaves an absolute token file path unchanged", () => {
+    let opened = "";
+    readToken("/secrets/bot.token", (p) => {
+      opened = p;
+      return "abs-token\n";
+    });
+    expect(opened).toBe("/secrets/bot.token");
+  });
+
   it("never echoes the token in any error path", () => {
     // Read succeeds but token is whitespace → empty error. The thrown message
     // must not contain the raw read contents.