feat: make it possible to get schema from a component

Does not work for reference object so far.

lib/bagger.ts

@@ -4,13 +4,14 @@ import { BaggerRequestBody } from './request_body';
 import { BaggerConfiguration, BaggerConfigurationInternal } from './configuration';
 import { OpenAPIObject } from 'openapi3-ts';
 import { BaggerParameter, ParameterType } from './parameters';
-import { BaggerComponentAdder } from './component';
+import { BaggerComponentAdder, BaggerComponentGetter } from './component';
 import { schemaStorage } from './schema_storage';
 import { JoiValidationSchema, swaggerToJoiValidation } from './utils/swagger_to_joi_validation';
 
 const internalConfiguration = new BaggerConfigurationInternal();
 const configuration = new BaggerConfiguration(internalConfiguration);
 const componentAdder = new BaggerComponentAdder(internalConfiguration);
+const componentGetter = new BaggerComponentGetter(internalConfiguration);
 
 /**
  * Creates a Response object
@@ -73,6 +74,13 @@ export function addComponent(): BaggerComponentAdder {
   return componentAdder;
 }
 
+/**
+ * Get a reusable component.
+ */
+export function getComponent(): BaggerComponentGetter {
+  return componentGetter;
+}
+
 /**
  * Create a request body used for defining a body in a bagger request
  * @example

lib/component.ts

@@ -31,6 +31,14 @@ export class BaggerSchemaComponent {
     }
   }
 
+  public getName(): string {
+    return this.name;
+  }
+
+  public getSchema(): Schema | ReferenceObject {
+    return this.schema;
+  }
+
   public compile(): { name: string; schema: SchemaObject | ReferenceObject } {
     return {
       name: this.name,
@@ -57,3 +65,15 @@ export class BaggerComponentAdder {
     return component;
   }
 }
+
+export class BaggerComponentGetter {
+  private internalConfiguration: BaggerConfigurationInternal;
+
+  public constructor(internalConfiguration: BaggerConfigurationInternal) {
+    this.internalConfiguration = internalConfiguration;
+  }
+
+  public getSchema(name: string): Schema {
+    return this.internalConfiguration.getSchemaComponent(name);
+  }
+}

lib/configuration.ts

@@ -11,6 +11,10 @@ import {
 import { cleanObject } from './utils/clean_object';
 import { validateSchema } from './utils/validate_schema';
 import { BaggerSchemaComponent, SchemaComponentObject } from './component';
+import { Schema } from '@hapi/joi';
+
+class BaggerMultipleComponentsWithSameNameFoundError extends Error {}
+class BaggerComponentNotFoundError extends Error {}
 
 interface SwaggerConfiguration {
   info: InfoObject;
@@ -87,6 +91,17 @@ export class BaggerConfigurationInternal {
     this.components.schemas.push(component);
   }
 
+  public getSchemaComponent(name: string): Schema {
+    const schemas = this.components.schemas.filter(schema => schema.getName() === name);
+    if (schemas.length === 0) {
+      throw new BaggerComponentNotFoundError();
+    }
+    if (schemas.length > 1) {
+      throw new BaggerMultipleComponentsWithSameNameFoundError();
+    }
+    return schemas[0].getSchema() as Schema;
+  }
+
   public setInfo(info: InfoObject): void {
     this.configuration.info = info;
   }