fix(settings): validate the add-provider wizard step before advancing (#2813)

apps/web/src/components/settings/AddProviderInstanceDialog.test.ts

@@ -0,0 +1,38 @@
+import { describe, expect, it } from "vite-plus/test";
+
+import { advanceInstanceWizard } from "./AddProviderInstanceDialog";
+
+describe("advanceInstanceWizard", () => {
+  it("advances from the Driver step even when the instance id is invalid", () => {
+    // The Driver step (index 0) does not own the Instance ID field, so an
+    // invalid id must not block leaving it.
+    expect(advanceInstanceWizard(0, 3, { instanceIdError: "Instance ID is required." })).toEqual({
+      kind: "advance",
+      step: 1,
+    });
+  });
+
+  it("blocks leaving the Identity step while the instance id is invalid", () => {
+    // Regression for #2813: clicking Next on the Identity step used to advance
+    // unconditionally, so the user reached the final step only for "Add
+    // instance" to silently no-op.
+    expect(advanceInstanceWizard(1, 3, { instanceIdError: "Instance ID is required." })).toEqual({
+      kind: "blocked",
+      error: "Instance ID is required.",
+    });
+  });
+
+  it("advances from the Identity step once the instance id is valid", () => {
+    expect(advanceInstanceWizard(1, 3, { instanceIdError: null })).toEqual({
+      kind: "advance",
+      step: 2,
+    });
+  });
+
+  it("never advances past the last step", () => {
+    expect(advanceInstanceWizard(2, 3, { instanceIdError: null })).toEqual({
+      kind: "advance",
+      step: 2,
+    });
+  });
+});

apps/web/src/components/settings/AddProviderInstanceDialog.tsx

@@ -108,6 +108,30 @@ function validateInstanceId(id: string, existing: ReadonlySet<string>): string |
   return null;
 }
 
+export type WizardAdvance =
+  | { readonly kind: "advance"; readonly step: number }
+  | { readonly kind: "blocked"; readonly error: string };
+
+/**
+ * Decide what clicking "Next" should do in the add-instance wizard. The
+ * Identity step (index 1) owns the Instance ID, so the wizard must not advance
+ * past it while the id is invalid — otherwise the user reaches the final step
+ * only for "Add instance" to silently no-op. Returns either the next step to
+ * move to, or the error that blocks advancing (mirrors the gate `handleSave`
+ * applies before submit).
+ */
+export function advanceInstanceWizard(
+  currentStep: number,
+  stepCount: number,
+  validation: { readonly instanceIdError: string | null },
+): WizardAdvance {
+  const blockingError = currentStep === 1 ? validation.instanceIdError : null;
+  if (blockingError !== null) {
+    return { kind: "blocked", error: blockingError };
+  }
+  return { kind: "advance", step: Math.min(stepCount - 1, currentStep + 1) };
+}
+
 interface AddProviderInstanceDialogProps {
   open: boolean;
   onOpenChange: (open: boolean) => void;
@@ -475,7 +499,19 @@ export function AddProviderInstanceDialog({ open, onOpenChange }: AddProviderIns
               {wizardStep === 0 ? "Cancel" : "Back"}
             </Button>
             {wizardStep < wizardSteps.length - 1 ? (
-              <Button size="sm" onClick={() => setWizardStep((step) => Math.min(2, step + 1))}>
+              <Button
+                size="sm"
+                onClick={() => {
+                  const advance = advanceInstanceWizard(wizardStep, wizardSteps.length, {
+                    instanceIdError,
+                  });
+                  if (advance.kind === "blocked") {
+                    setHasAttemptedSubmit(true);
+                    return;
+                  }
+                  setWizardStep(advance.step);
+                }}
+              >
                 Next
               </Button>
             ) : (