feat(api): get certslug route (#50515)

Co-authored-by: Sboonny <muhammed@freecodecamp.org>
Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>
Co-authored-by: moT01 <20648924+moT01@users.noreply.github.com>

api/src/utils/common-challenge-functions.ts

@@ -59,6 +59,7 @@ type CompletedChallengeFile = {
   path?: string | null;
 };
 
+// TODO: Should probably prefer `import{CompletedChallenge}from'@prisma/client'` instead of defining it here
 export type CompletedChallenge = {
   id: string;
   solution?: string | null;

api/src/utils/error-formatting.ts

@@ -1,4 +1,7 @@
 import { ErrorObject } from 'ajv';
+import { certTypes } from '../../../shared/config/certification-settings';
+
+type CertLogs = (typeof certTypes)[keyof typeof certTypes];
 
 type FormattedError = {
   type: 'error';
@@ -47,6 +50,30 @@ export const formatProjectCompletedValidation = (
       };
 };
 
+/**
+ * Format validation errors for /project-completed.
+ *
+ * @param errors An array of validation errors.
+ * @returns Formatted errors that can be used in the response.
+ */
+export const formatCertificationValidation = (
+  errors: ErrorObject[]
+): FormattedError => {
+  const error = getError(errors);
+
+  return error.instancePath === '' &&
+    Object.values(certTypes).includes(error.params.missingProperty as CertLogs)
+    ? ({
+        type: 'error',
+        message:
+          'You have not provided the valid param for us to display the certification.'
+      } as const)
+    : ({
+        type: 'error',
+        message: 'That does not appear to be a valid certification request.'
+      } as const);
+};
+
 /**
  * Format validation errors for /coderoad-challenge-completed.
  *