[ML] Fixing wizard validation delay (elastic#45265)

* [ML] Fixing wizard validation delay

* changes based on review

Author: jgowdyelastic

x-pack/legacy/plugins/ml/public/jobs/new_job_new/common/job_validator/job_validator.ts

@@ -37,7 +37,7 @@ export class JobValidator {
   private _jobCreator: JobCreatorType;
   private _validationSummary: ValidationSummary;
   private _lastJobConfig: string;
-  private _validateTimeout: NodeJS.Timeout;
+  private _validateTimeout: ReturnType<typeof setTimeout> | null = null;
   private _existingJobsAndGroups: ExistingJobsAndGroups;
   private _basicValidations: BasicValidations = {
     jobId: { valid: true },
@@ -46,6 +46,7 @@ export class JobValidator {
     bucketSpan: { valid: true },
     duplicateDetectors: { valid: true },
   };
+  private _validating: boolean = false;
 
   constructor(jobCreator: JobCreatorType, existingJobsAndGroups: ExistingJobsAndGroups) {
     this._jobCreator = jobCreator;
@@ -54,25 +55,30 @@ export class JobValidator {
       basic: false,
       advanced: false,
     };
-    this._validateTimeout = setTimeout(() => {}, 0);
     this._existingJobsAndGroups = existingJobsAndGroups;
   }
 
-  public validate() {
+  public validate(callback: () => void) {
+    this._validating = true;
     const formattedJobConfig = this._jobCreator.formattedJobJson;
-    return new Promise((resolve: () => void) => {
-      // only validate if the config has changed
-      if (formattedJobConfig !== this._lastJobConfig) {
+    // only validate if the config has changed
+    if (formattedJobConfig !== this._lastJobConfig) {
+      if (this._validateTimeout !== null) {
+        // clear any previous on going validation timeouts
         clearTimeout(this._validateTimeout);
-        this._lastJobConfig = formattedJobConfig;
-        this._validateTimeout = setTimeout(() => {
-          this._runBasicValidation();
-          resolve();
-        }, VALIDATION_DELAY_MS);
-      } else {
-        resolve();
       }
-    });
+      this._lastJobConfig = formattedJobConfig;
+      this._validateTimeout = setTimeout(() => {
+        this._runBasicValidation();
+        this._validating = false;
+        this._validateTimeout = null;
+        callback();
+      }, VALIDATION_DELAY_MS);
+    } else {
+      // _validating is still true if there is a previous validation timeout on going.
+      this._validating = this._validateTimeout !== null;
+    }
+    callback();
   }
 
   private _resetBasicValidations() {
@@ -135,4 +141,8 @@ export class JobValidator {
   public set advancedValid(valid: boolean) {
     this._validationSummary.advanced = valid;
   }
+
+  public get validating(): boolean {
+    return this._validating;
+  }
 }

x-pack/legacy/plugins/ml/public/jobs/new_job_new/pages/components/job_details_step/job_details.tsx

@@ -37,7 +37,8 @@ export const JobDetailsStep: FC<Props> = ({
     const active =
       jobValidator.jobId.valid &&
       jobValidator.modelMemoryLimit.valid &&
-      jobValidator.groupIds.valid;
+      jobValidator.groupIds.valid &&
+      jobValidator.validating === false;
     setNextActive(active);
   }, [jobValidatorUpdated]);
 

x-pack/legacy/plugins/ml/public/jobs/new_job_new/pages/components/pick_fields_step/pick_fields.tsx

@@ -30,7 +30,8 @@ export const PickFieldsStep: FC<StepProps> = ({ setCurrentStep, isCurrentStep })
     const active =
       jobCreator.detectors.length > 0 &&
       jobValidator.bucketSpan.valid &&
-      jobValidator.duplicateDetectors.valid;
+      jobValidator.duplicateDetectors.valid &&
+      jobValidator.validating === false;
     setNextActive(active);
   }, [jobValidatorUpdated]);
 

x-pack/legacy/plugins/ml/public/jobs/new_job_new/pages/new_job/wizard.tsx

@@ -86,11 +86,9 @@ export const Wizard: FC<Props> = ({
   );
 
   useEffect(() => {
-    // IIFE to run the validation. the useEffect callback can't be async
-    (async () => {
-      await jobValidator.validate();
+    jobValidator.validate(() => {
       setJobValidatorUpdate(jobValidatorUpdated);
-    })();
+    });
 
     // if the job config has changed, reset the highestStep
     // compare a stringified config to ensure the configs have actually changed