JavaScriptSolidServer · melvincarvalho · May 1, 2026 · May 1, 2026 · May 1, 2026 · May 1, 2026
@@ -32,6 +32,49 @@ program
   .description('JavaScript Solid Server - A minimal, fast, JSON-LD native Solid server')
   .version(pkg.version);
 
+/**
+ * Convert a camelCase option name back to its kebab-case CLI form for
+ * error messages (`singleUserName` → `single-user-name`).
+ */
+function camelToKebab (name) {
+  return name.replace(/([a-z0-9])([A-Z])/g, '$1-$2').toLowerCase();
+}
+
+/**
+ * Reject any option value that looks like another flag (#103).
+ *
+ * Commander happily consumes the next argv as a value, so
+ *   `jss start --single-user-name --idp`
+ * silently sets `singleUserName="--idp"` and the IdP flag is lost.
+ * This validator runs as a `preAction` hook for every subcommand, so
+ * any option with a missing value gets a clear error instead of a
+ * confusing downstream failure ("issuer has no registration endpoint",
+ * "Single-user: --idp" in the banner, etc.).
+ */
+program.hook('preAction', (_thisCommand, actionCommand) => {
+  const opts = actionCommand.opts();
+  for (const [key, value] of Object.entries(opts)) {
+    const flag = camelToKebab(key);
+    if (typeof value === 'string' && value.startsWith('--')) {
+      console.error(
+        `Error: --${flag} value "${value}" looks like a flag, not a value.\n` +
+        `Hint: did you forget to provide a value? e.g. --${flag} someValue`
+      );
+      process.exit(1);
+    }
+    // Numeric options (parseInt-coerced like --port) silently produce
+    // NaN when given a flag like `--idp`. Catch that too — same root
+    // cause, different surface.
+    if (typeof value === 'number' && Number.isNaN(value)) {
+      console.error(
+        `Error: --${flag} got a non-numeric value (parsed as NaN).\n` +
+        `Hint: did you forget to provide a number? e.g. --${flag} 8080`
+      );
+      process.exit(1);
+    }
+  }
+});
+
 /**
  * Start command
  */

@@ -0,0 +1,88 @@
+/**
+ * Regression tests for #103 — `bin/jss.js` must reject option values
+ * that look like flags (e.g. `--single-user-name --idp`) instead of
+ * silently using `--idp` as the username and breaking IdP setup.
+ *
+ * These spawn the CLI as a subprocess and assert exit-code + stderr.
+ */
+
+import { describe, it } from 'node:test';
+import assert from 'node:assert';
+import { spawnSync } from 'node:child_process';
+import os from 'node:os';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const BIN = path.join(__dirname, '..', 'bin', 'jss.js');
+
+// Timeout cap so the suite can never hang if the validator regresses
+// and `start` actually tries to bind a port instead of exiting early.
+const RUN_TIMEOUT_MS = 10_000;
+
+function runCli(args) {
+  const r = spawnSync(process.execPath, [BIN, ...args], {
+    encoding: 'utf8',
+    timeout: RUN_TIMEOUT_MS,
+    killSignal: 'SIGKILL'
+  });
+  // spawnSync sets `signal` to the kill signal when timeout fires. Treat
+  // that as a hard test failure rather than letting downstream
+  // assertions on stderr accidentally pass.
+  assert.strictEqual(
+    r.signal, null,
+    `CLI did not exit within ${RUN_TIMEOUT_MS}ms — likely the preAction ` +
+    `validator regressed and \`start\` is actually trying to listen. ` +
+    `args: ${JSON.stringify(args)}; partial stderr: ${r.stderr}`
+  );
+  return r;
+}
+
+describe('bin/jss.js — flag-like option values (#103)', () => {
+  it('rejects `--single-user-name --idp` with a clear error', () => {
+    const r = runCli(['start', '--single-user-name', '--idp']);
+    assert.notStrictEqual(r.status, 0, 'exit code should be non-zero');
+    assert.match(r.stderr, /--single-user-name value "--idp" looks like a flag/);
+    assert.match(r.stderr, /Hint: did you forget to provide a value\?/);
+  });
+
+  it('rejects another option swallowing a flag (covers --idp-issuer too)', () => {
+    // Commander's behaviour: it greedily consumes the next argv as the
+    // value, which is the whole reason the bug exists. We use a flag
+    // commander doesn't know about so commander doesn't reroute it
+    // through its own argument-count error. The dummy name is
+    // collision-proof — if anyone ever adds a real `--bogus-...` flag
+    // matching this pattern, the duplication is the bigger problem.
+    const FAKE_FLAG = '--__jss103_unlikely_cli_option__';
+    const r = runCli(['start', '--idp-issuer', FAKE_FLAG]);
+    assert.notStrictEqual(r.status, 0);
+    assert.match(
+      r.stderr,
+      new RegExp(`--idp-issuer value "${FAKE_FLAG}" looks like a flag`)
+    );
+  });
+
+  it('rejects `--port --idp` (numeric option → NaN) with helpful error', () => {
+    const r = runCli(['start', '--port', '--idp']);
+    assert.notStrictEqual(r.status, 0);
+    assert.match(r.stderr, /--port got a non-numeric value/);
+    assert.match(r.stderr, /Hint: did you forget to provide a number\?/);
+  });
+
+  it('accepts a real value and reaches normal config processing', () => {
+    // --print-config exits 0 cleanly after dumping config; this proves
+    // the validator doesn't false-positive on legitimate values.
+    // Use os.tmpdir() rather than a hard-coded /tmp/... so the test is
+    // portable across platforms (and matches the rest of the suite).
+    const tmpRoot = path.join(os.tmpdir(), 'jss-103-sanity-doesnotneedtoexist');
+    const r = runCli(['start',
+      '--port', '4582',
+      '--root', tmpRoot,
+      '--single-user-name', 'alice',
+      '--print-config'
+    ]);
+    assert.strictEqual(r.status, 0,
+      `expected clean exit, got ${r.status}; stderr: ${r.stderr}`);
+    assert.match(r.stdout, /Configuration:/);
+  });
+});