Modify validation to have a more user friendly API

* Adding a container type to be returned from validate function
* Modifying JsonRulesEngineFactChecker to throw with error information if check addition fails on validation

Signed-off-by: Jussi Hallila <jussi@hallila.com>

plugins/tech-insights-common/api-report.md

@@ -4,6 +4,7 @@
 
 ```ts
 import { Config } from '@backstage/config';
+import { CustomErrorBase } from '@backstage/errors';
 import { DateTime } from 'luxon';
 import { Logger as Logger_2 } from 'winston';
 import { PluginEndpointDiscovery } from '@backstage/backend-common';
@@ -30,6 +31,28 @@ export type CheckResult = {
   check: CheckResponse;
 };
 
+// @public
+export class CheckValidationError extends CustomErrorBase {
+  constructor({
+    message,
+    cause,
+    errors,
+  }: {
+    message: string;
+    cause?: Error;
+    errors?: any;
+  });
+  // (undocumented)
+  errors?: any;
+}
+
+// @public
+export type CheckValidationResponse = {
+  valid: boolean;
+  message?: string;
+  errors?: any;
+};
+
 // @public
 export interface FactChecker<
   CheckType extends TechInsightCheck,
@@ -38,7 +61,7 @@ export interface FactChecker<
   addCheck(check: CheckType): Promise<CheckType>;
   getChecks(): Promise<CheckType[]>;
   runChecks(entity: string, checks: string[]): Promise<CheckResultType[]>;
-  validate(check: CheckType): Promise<boolean>;
+  validate(check: CheckType): Promise<CheckValidationResponse>;
 }
 
 // @public

plugins/tech-insights-common/package.json

@@ -31,6 +31,7 @@
   },
   "dependencies": {
     "@backstage/backend-common": "^0.9.0",
+    "@backstage/errors": "^0.1.2",
     "@backstage/config": "^0.1.8",
     "@types/luxon": "^2.0.5",
     "luxon": "^2.0.2",

plugins/tech-insights-common/src/checks.ts

@@ -15,6 +15,7 @@
  */
 import { TechInsightsStore } from './persistence';
 import { CheckResponse, FactResponse } from './responses';
+import { CustomErrorBase } from '@backstage/errors';
 
 /**
  * A factory wrapper to construct FactChecker implementations.
@@ -82,7 +83,7 @@ export interface FactChecker<
    * @param check - The check to be validated
    * @returns - Validation result
    */
-  validate(check: CheckType): Promise<boolean>;
+  validate(check: CheckType): Promise<CheckValidationResponse>;
 }
 
 /**
@@ -171,3 +172,39 @@ export interface TechInsightCheck {
    */
   failureMetadata?: Record<string, any>;
 }
+
+/**
+ * Validation response from CheckValidator
+ *
+ * May contain additional data for display purposes
+ * @public
+ */
+export type CheckValidationResponse = {
+  valid: boolean;
+  message?: string;
+  errors?: any;
+};
+
+/**
+ * Error object for Validation Errors
+ *
+ * Can be used to short circuit larger execution paths instead of passing validation response around
+ *
+ * @public
+ */
+export class CheckValidationError extends CustomErrorBase {
+  errors?: any;
+
+  constructor({
+    message,
+    cause,
+    errors,
+  }: {
+    message: string;
+    cause?: Error;
+    errors?: any;
+  }) {
+    super(message, cause);
+    this.errors = errors;
+  }
+}