refactor(scenario): remove validateCode — assertions live in execCode

- drop validateCode column, DTOs, service mappings, and scheduler branch
- remove parseValidateResult helper and ValidateResult interface
- inject playwright expect into code executor for direct use in execCode
- strip validateCode from MCP tool schemas, client types, and UI forms

client/src/api/client.ts

@@ -274,14 +274,12 @@ export const scenarioCredentials = {
 export interface CreateStepPayload {
   title?: string;
   execCode?: string;
-  validateCode?: string;
 }
 
 export interface UpdateStepPayload {
   title?: string;
   order?: number;
   execCode?: string;
-  validateCode?: string;
 }
 
 export const steps = {

client/src/api/types.ts

@@ -66,7 +66,6 @@ export interface ScenarioStep {
   order: number;
   title: string | null;
   execCode: string | null;
-  validateCode: string | null;
   createdAt: string;
   updatedAt: string;
 }

client/src/i18n/locales/en.json

@@ -183,9 +183,7 @@
     "form_session_placeholder": "e.g. my-session",
     "form_session_required": "Session name is required",
     "form_exec_code": "Exec code",
-    "form_exec_code_placeholder": "return await page.title();",
+    "form_exec_code_placeholder": "return await page.title();"
-    "form_validate_code": "Validate code",
-    "form_validate_code_placeholder": "return { success: result !== null, description: \"…\" };"
   },
   "runs": {
     "title": "Runs",

client/src/pages/scenario/CreateStepPage.tsx

@@ -16,7 +16,6 @@ export function CreateStepPage() {
   const [scenario, setScenario] = useState<Scenario | null>(null);
   const [title, setTitle] = useState('');
   const [execCode, setExecCode] = useState('');
-  const [validateCode, setValidateCode] = useState('');
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
@@ -36,7 +35,6 @@ export function CreateStepPage() {
       await steps.create(id!, {
         title: title.trim() || undefined,
         execCode: execCode.trim() || undefined,
-        validateCode: validateCode.trim() || undefined,
       });
       toast.success('Step created');
       navigate(`/scenarios/${id}`);
@@ -77,10 +75,6 @@ export function CreateStepPage() {
               <label className={styles.fieldLabel}>{t('steps.form_exec_code')}</label>
               <CodeEditor value={execCode} onChange={setExecCode} rows={6} />
             </div>
-            <div className={styles.formField}>
-              <label className={styles.fieldLabel}>{t('steps.form_validate_code')}</label>
-              <CodeEditor value={validateCode} onChange={setValidateCode} rows={6} />
-            </div>
           </div>
 
           <div className={styles.formActions}>

client/src/pages/scenario/EditStepPage.tsx

@@ -17,7 +17,6 @@ export function EditStepPage() {
   const [step, setStep] = useState<ScenarioStep | null>(null);
   const [title, setTitle] = useState('');
   const [execCode, setExecCode] = useState('');
-  const [validateCode, setValidateCode] = useState('');
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -30,7 +29,6 @@ export function EditStepPage() {
         setStep(st);
         setTitle(st.title ?? '');
         setExecCode(st.execCode ?? '');
-        setValidateCode(st.validateCode ?? '');
       })
       .catch((err: Error) => setError(err.message))
       .finally(() => setLoading(false));
@@ -44,7 +42,6 @@ export function EditStepPage() {
       await steps.update(id!, stepId!, {
         title: title.trim() || undefined,
         execCode: execCode.trim() || undefined,
-        validateCode: validateCode.trim() || undefined,
       });
       toast.success('Step updated');
       navigate(`/scenarios/${id}`);
@@ -88,10 +85,6 @@ export function EditStepPage() {
                 <label className={styles.fieldLabel}>{t('steps.form_exec_code')}</label>
                 <CodeEditor value={execCode} onChange={setExecCode} rows={6} />
               </div>
-              <div className={styles.formField}>
-                <label className={styles.fieldLabel}>{t('steps.form_validate_code')}</label>
-                <CodeEditor value={validateCode} onChange={setValidateCode} rows={6} />
-              </div>
             </div>
 
             <div className={styles.formActions}>

package-lock.json

@@ -3532,6 +3532,21 @@
         "url": "https://opencollective.com/pkgr"
       }
     },
+    "node_modules/@playwright/test": {
+      "version": "1.59.1",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.59.1.tgz",
+      "integrity": "sha512-PG6q63nQg5c9rIi4/Z5lR5IVF7yU5MqmKaPOe0HSc0O2cX1fPi96sUQu5j7eo4gKCkB2AnNGoWt7y4/Xx3Kcqg==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.59.1"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/@polka/url": {
       "version": "1.0.0-next.29",
       "resolved": "https://registry.npmjs.org/@polka/url/-/url-1.0.0-next.29.tgz",
@@ -15942,6 +15957,7 @@
         "@nestjs/schedule": "^6.1.1",
         "@nestjs/swagger": "^11.2.6",
         "@nestjs/typeorm": "^11.0.1",
+        "@playwright/test": "^1.59.1",
         "acorn": "^8.16.0",
         "better-sqlite3": "^12.8.0",
         "class-transformer": "^0.5.1",

server/package.json

@@ -27,6 +27,7 @@
     "@nestjs/schedule": "^6.1.1",
     "@nestjs/swagger": "^11.2.6",
     "@nestjs/typeorm": "^11.0.1",
+    "@playwright/test": "^1.59.1",
     "acorn": "^8.16.0",
     "better-sqlite3": "^12.8.0",
     "class-transformer": "^0.5.1",

server/src/code-executor/code-executor.service.ts

@@ -6,6 +6,7 @@ import {
 import { TraceLogger } from "../common/trace-logger";
 import { parse } from "acorn";
 import type { Page, BrowserContext } from "playwright";
+import { expect as playwrightExpect } from "@playwright/test";
 import { dumpDom } from "./dom-helpers";
 import type { EnvironmentData } from "../environment/environment.entity";
 
@@ -123,19 +124,28 @@ export class CodeExecutorService {
             "helpers",
             "console",
             "snippetArgs",
+            "expect",
             `return (async (page, context, helpers, ...args) => { ${snippetCode} })(page, context, helpers, ...snippetArgs)`,
           );
-          return snippetFn(page, context, pageHelpers, fakeConsole, args);
+          return snippetFn(
+            page,
+            context,
+            pageHelpers,
+            fakeConsole,
+            args,
+            playwrightExpect,
+          );
         },
       };
 
-      // Passing `console` as a named parameter shadows the global in the script scope.
+      // Passing `console` and `expect` as named parameters exposes them in script scope.
       const fn = new Function(
         "page",
         "context",
         "helpers",
         "console",
         "result",
+        "expect",
         `return (async (page, context, helpers) => { ${code} })(page, context, helpers)`,
       );
       this.logger.debug("Executing user code");
@@ -145,6 +155,7 @@ export class CodeExecutorService {
         pageHelpers,
         fakeConsole,
         result,
+        playwrightExpect,
       );
       return { result: execResult };
     } catch (err) {

server/src/mcp/mcp.service.ts

@@ -505,10 +505,6 @@ export class McpService {
             .string()
             .optional()
             .describe("Playwright JS code to execute (exec steps)"),
-          validateCode: z
-            .string()
-            .optional()
-            .describe("Validation JS code returning { success, description }"),
         },
       },
       async ({ scenarioId, ...dto }) => {
@@ -569,7 +565,6 @@ export class McpService {
             .describe("New step type"),
           title: z.string().optional().describe("New step title"),
           execCode: z.string().optional().describe("New exec code"),
-          validateCode: z.string().optional().describe("New validation code"),
         },
       },
       async ({ scenarioId, stepId, ...dto }) => {
@@ -785,11 +780,6 @@ export class McpService {
                   .nullable()
                   .optional()
                   .describe("Exec/sign code"),
-                validateCode: z
-                  .string()
-                  .nullable()
-                  .optional()
-                  .describe("Validation code"),
               }),
             )
             .describe("Ordered list of steps"),

server/src/scenario/dto/create-scenario-step.dto.ts

@@ -13,12 +13,4 @@ export class CreateScenarioStepDto {
   @IsNotEmpty()
   execCode?: string;
 
-  @ApiPropertyOptional({
-    example:
-      'return { success: result !== null, description: "title present" };',
-  })
-  @IsOptional()
-  @IsString()
-  @IsNotEmpty()
-  validateCode?: string;
 }

server/src/scenario/dto/scenario-export.dto.ts

@@ -23,11 +23,6 @@ export class ScenarioStepExportDto {
   @IsNotEmpty()
   execCode: string | null;
 
-  @ApiPropertyOptional()
-  @IsOptional()
-  @IsString()
-  @IsNotEmpty()
-  validateCode: string | null;
 }
 
 export class ScenarioExportDto {

server/src/scenario/dto/update-scenario-step.dto.ts

@@ -19,9 +19,4 @@ export class UpdateScenarioStepDto {
   @IsNotEmpty()
   execCode?: string;
 
-  @ApiPropertyOptional()
-  @IsOptional()
-  @IsString()
-  @IsNotEmpty()
-  validateCode?: string;
 }

server/src/scenario/scenario-scheduler.service.ts

@@ -17,11 +17,6 @@ import { ScenarioService } from "./scenario.service";
 import { SnippetService } from "../snippet/snippet.service";
 import { EnvironmentEntity, EnvironmentData } from "../environment/environment.entity";
 
-interface ValidateResult {
-  success: boolean;
-  description?: string;
-}
-
 interface BrowserHandle {
   browser: Browser;
   context: BrowserContext;
@@ -188,25 +183,6 @@ export class ScenarioSchedulerService {
         snips,
       );
 
-      if (step.validateCode) {
-        this.codeExecutor.validate(step.validateCode);
-        const { result } = await this.codeExecutor.execute(
-          page,
-          context,
-          step.validateCode,
-          this.stepLogger(stepRun.id, stepRun.runId),
-          getStepOutput,
-          creds,
-          env,
-          snips,
-          execOutput,
-        );
-        const vr = this.parseValidateResult(result);
-        if (!vr.success) throw new Error(vr.description ?? "Validation failed");
-        await this.passStepRun(stepRun, vr.description ?? null, execOutput);
-        return;
-      }
-
       await this.passStepRun(stepRun, null, execOutput);
     } catch (err) {
       const msg = (err as Error).message ?? String(err);
@@ -250,21 +226,6 @@ export class ScenarioSchedulerService {
     }
   }
 
-  // ── Validation helper ──────────────────────────────────────────────────────
-
-  private parseValidateResult(raw: unknown): ValidateResult {
-    if (typeof raw === "boolean") return { success: raw };
-    if (raw && typeof raw === "object") {
-      const r = raw as Record<string, unknown>;
-      return {
-        success: Boolean(r["success"]),
-        description:
-          r["description"] != null ? String(r["description"]) : undefined,
-      };
-    }
-    return { success: Boolean(raw) };
-  }
-
   // ── Pass / fail helpers ────────────────────────────────────────────────────
 
   private async passStepRun(

server/src/scenario/scenario-step.entity.ts

@@ -32,9 +32,6 @@ export class ScenarioStepEntity {
   @Column({ type: "text", nullable: true })
   execCode: string | null;
 
-  @Column({ type: "text", nullable: true })
-  validateCode: string | null;
-
   @CreateDateColumn()
   createdAt: Date;
 

server/src/scenario/scenario.service.ts

@@ -124,7 +124,6 @@ export class ScenarioService {
         scenarioId,
         title: dto.title ?? null,
         execCode: dto.execCode ?? null,
-        validateCode: dto.validateCode ?? null,
       }),
     );
     await this.normalizeStepOrder(scenarioId);
@@ -156,7 +155,6 @@ export class ScenarioService {
       order: step.order,
       title: dto.title ?? step.title,
       execCode: dto.execCode ?? step.execCode,
-      validateCode: dto.validateCode ?? step.validateCode,
     });
     await this.stepRepo.save(step);
 
@@ -404,7 +402,6 @@ export class ScenarioService {
       steps: scenario.steps.map((s) => ({
         title: s.title,
         execCode: s.execCode,
-        validateCode: s.validateCode,
       })),
     };
   }
@@ -436,7 +433,6 @@ export class ScenarioService {
           order: index,
           title: s.title ?? null,
           execCode: s.execCode ?? null,
-          validateCode: s.validateCode ?? null,
         }),
       );
       await this.stepRepo.save(steps);

server/test/scenario.controller.spec.ts

@@ -477,7 +477,6 @@ describe("ScenarioController", () => {
         order: 1,
         sessionName: "s",
         execCode: "return 1;",
-        validateCode: "return true;",
       });
 
       const res = await request(app.getHttpServer())
@@ -536,25 +535,6 @@ describe("ScenarioController", () => {
       expect(step).not.toHaveProperty("updatedAt");
     });
 
-    it("exports null validateCode as null", async () => {
-      const sc = await createScenario("export-null-validate");
-      await createStep(sc.id, {
-        order: 0,
-        sessionName: "s",
-        execCode: "return 1;",
-      });
-
-      const res = await request(app.getHttpServer())
-        .get(`/scenarios/${sc.id}/export`)
-        .expect(200);
-
-      const exported = yamlParse(res.text) as {
-        steps: Array<{ validateCode: string | null }>;
-      };
-
-      expect(exported.steps[0].validateCode).toBeNull();
-    });
-
     it("returns 404 for unknown scenario", async () => {
       await request(app.getHttpServer())
         .get("/scenarios/00000000-0000-0000-0000-000000000001/export")
@@ -572,17 +552,14 @@ describe("ScenarioController", () => {
           {
             sessionName: "s",
             execCode: '{"keyId":"k","environmentName":"e"}',
-            validateCode: null,
           },
           {
             sessionName: "s",
             execCode: "return 1;",
-            validateCode: "return true;",
           },
           {
             sessionName: "s",
             execCode: '{"keyId":"k"}',
-            validateCode: null,
           },
         ],
       };
@@ -622,7 +599,6 @@ describe("ScenarioController", () => {
         order: 0,
         sessionName: "rs",
         execCode: "return 42;",
-        validateCode: "return true;",
       });
 
       const exportRes = await request(app.getHttpServer())
@@ -630,7 +606,7 @@ describe("ScenarioController", () => {
         .expect(200);
 
       const exported = yamlParse(exportRes.text) as {
-        steps: Array<{ execCode: string; validateCode: string | null }>;
+        steps: Array<{ execCode: string }>;
       };
 
       const importRes = await request(app.getHttpServer())
@@ -643,9 +619,6 @@ describe("ScenarioController", () => {
       expect(importRes.body.steps[0].execCode).toBe(
         exported.steps[0].execCode,
       );
-      expect(importRes.body.steps[0].validateCode).toBe(
-        exported.steps[0].validateCode,
-      );
     });
 
     it("imports with empty steps array", async () => {