fix(deploy): remove unreachable null-signer guard in resolveSignerSetup (#110)

* fix(deploy): remove unreachable null-signer guard in resolveSignerSetup

The throw at signerMode.ts:142-149 could never fire: shouldResolveUserSigner()
returns true whenever publishToPlayground is true, so resolveSigner() in the
preflight has already either produced a ResolvedSigner or rethrown before
resolveSignerSetup is called. Replace the dead branch with a non-null assertion
and a comment explaining the invariant so the next refactor doesn't silently
reintroduce it.

Closes #104.

* chore: add changeset for dead-signer-guard fix

* test(deploy): remove test for unreachable null-signer path in resolveSignerSetup

Author: EnderOfWorlds007

.changeset/fix-dead-signer-guard.md

@@ -0,0 +1,5 @@
+---
+"playground-cli": patch
+---
+
+Remove unreachable null-signer guard in `resolveSignerSetup` (`signerMode.ts`). The dead `throw` could never fire because `shouldResolveUserSigner()` guarantees a signer is resolved before `resolveSignerSetup` is called when `--playground` is set. No user-visible behaviour change.

src/utils/deploy/signerMode.test.ts

@@ -23,16 +23,6 @@ describe("resolveSignerSetup — dev mode", () => {
         expect(result.publishSigner).toBeNull();
     });
 
-    it("publishToPlayground without a userSigner throws a helpful message", () => {
-        expect(() =>
-            resolveSignerSetup({
-                mode: "dev",
-                userSigner: null,
-                publishToPlayground: true,
-            }),
-        ).toThrow(/dot init|--playground/);
-    });
-
     it("publishToPlayground with session userSigner adds one playground approval and leaves auth empty", () => {
         const user = fakeSigner("session");
         const result = resolveSignerSetup({

src/utils/deploy/signerMode.ts

@@ -138,14 +138,14 @@ export function resolveSignerSetup(opts: ResolveOptions): DeploySignerSetup {
     // Playground publish always uses the user's signer so ownership ties to
     // their address — otherwise the registry would record a shared dev key
     // and the myApps view would be useless.
+    //
+    // userSigner is guaranteed non-null here: shouldResolveUserSigner() returns
+    // true whenever publishToPlayground is true, so resolveSigner() in the
+    // preflight has already either resolved a signer or thrown before we reach
+    // this point. The null guard that previously lived here was unreachable.
     let publishSigner: ResolvedSigner | null = null;
     if (opts.publishToPlayground) {
-        if (!opts.userSigner) {
-            throw new Error(
-                'Publishing to Playground requires a logged-in account. Run "dot init" first, or drop --playground.',
-            );
-        }
-        publishSigner = opts.userSigner;
+        publishSigner = opts.userSigner!;
         approvals.push({ phase: "playground", label: "Publish to Playground registry" });
     }