From c4a403e8071159eefb1dcda3cb611e0884bde58e Mon Sep 17 00:00:00 2001
From: Rainer Killinger <killinge@hrz.uni-frankfurt.de>
Date: Tue, 7 May 2019 11:32:22 +0200
Subject: [PATCH] refactor: reintroduce validateThing method

---
 src/common.ts   | 14 ++++++++++++++
 src/validate.ts | 29 +++++++++++++++++++++++++----
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/src/common.ts b/src/common.ts
index 02a49104..a713e0f1 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -182,6 +182,20 @@ export function isSchemaWithDefinitions(schema: JSONSchema): schema is SchemaWit
   return typeof schema.definitions !== 'undefined';
 }
 
+// tslint:disable: completed-docs
+/**
+ * Guard method for determining if an object (a thing) has a type property with a type of string
+ *
+ * @param thing An object (thing)
+ */
+export function isThingWithType(thing: unknown): thing is { type: string; } {
+  return typeof thing === 'object' &&
+         thing !== null &&
+         'type' in thing &&
+         typeof (thing as { type: string; }).type === 'string';
+}
+// tslint:enable: completed-docs
+
 /**
  * Get path that contains a tsconfig.json
  *
diff --git a/src/validate.ts b/src/validate.ts
index 0efb50c2..0e5251f6 100644
--- a/src/validate.ts
+++ b/src/validate.ts
@@ -18,7 +18,13 @@ import {PathLike} from 'fs';
 import {Schema, Validator as JSONSchemaValidator, ValidatorResult} from 'jsonschema';
 import * as mustache from 'mustache';
 import {basename, join, resolve} from 'path';
-import {ExpectableValidationErrors, globPromisified, readFilePromisified, writeFilePromisified} from './common';
+import {
+  ExpectableValidationErrors,
+  globPromisified,
+  isThingWithType,
+  readFilePromisified,
+  writeFilePromisified,
+} from './common';
 
 /**
  * StAppsCore validator
@@ -74,12 +80,28 @@ export class Validator {
   }
 
   /**
-   * Validates anything against a given schema name
+   * Validates anything against a given schema name or infers schema name from object
    *
    * @param instance Instance to validate
    * @param schema Name of schema to validate instance against or the schema itself
    */
-  public validate(instance: unknown, schema: string | Schema): ValidatorResult {
+  public validate(instance: unknown, schema?: string | Schema): ValidatorResult {
+    if (typeof schema === 'undefined') {
+      if (isThingWithType(instance)) {
+        // schema name can be infered from type string
+        // tslint:disable-next-line: completed-docs
+        const schemaSuffix = (instance as { type: string; }).type.split(' ')
+        .map((part: string) => {
+            return part.substr(0, 1)
+                       .toUpperCase() + part.substr(1);
+          })
+        .join('');
+        const schemaName = `SC${schemaSuffix}`;
+
+        return this.validate(instance, schemaName);
+      }
+      throw new Error('Instance.type does not exist.');
+    }
     if (typeof schema === 'string') {
       // if you want to access a schema that is contained in the validator object
       if (typeof this.schemas[schema] !== 'object') {
@@ -89,7 +111,6 @@ export class Validator {
       return this.validator.validate(instance, this.schemas[schema]);
     }
 
-    // if you have a schema and want to validate it directly
     return this.validator.validate(instance, schema);
   }
 }