implementation of knex crud handler

lib/HttpHandler.ts

@@ -0,0 +1,5 @@
+import { Router } from 'express';
+
+export class HttpHandler {
+  public abstract register_handlers(router: Router): void;
+}

lib/KnexCrudHandler.ts

@@ -1,39 +1,30 @@
-import { Request, Response } from 'express';
+import { Request, Response, Router } from 'express';
 import { http } from '@scode/consts';
-import { try_parse_json } from '@scode/utilities';
 import { KnexCrudOptions } from './KnexCrudOptions';
 import { CrudHandler } from './CrudHandler';
+import { Knex } from './KnexInterface';
+import { HttpHandler } from './HttpHandler';
 
-export class KnexCrudHandler implements CrudHandler {
+export class KnexCrudHandler extends HttpHandler implements CrudHandler {
   protected table: string;
   protected columns: Array<string>;
   protected options: KnexCrudOptions;
+  protected knex: Knex;
 
   public constructor (
     table: string,
     columns: Array<string>,
     options: KnexCrudOptions = {}
   ) {
+    super ();
     this.table = table;
     this.columns = columns;
     this.options = options;
+    if (this.columns.filter ((val) => val.toLowerCase () === 'id').length > 0) {
+      throw new Error (
+        'the column id cannot be made available to modification'
+      );
     }
-
-  private call_auth (
-    auth?: Function,
-    req: Request,
-    res: Response
-  ): Promise<boolean> {
-    if (typeof auth === 'undefined')
-      return true;
-
-    const promise = new Promise ((resolve) => {
-      const result = auth (req, res, resolve);
-      if (typeof result !== 'undefined')
-        resolve (result);
-    });
-
-    return promise;
   }
 
   protected validate_body (
@@ -42,32 +33,138 @@ export class KnexCrudHandler implements CrudHandler {
   ): Promise<object> | object {
     if (typeof req.body === 'undefined') {
       res.status (http.status_bad_request);
-      res.end ();
+      res.end ('body was undefined');
       return null;
     }
-    return try_parse_json (req.body);
+    try {
+      return JSON.parse (req.body);
+    }
+    catch (e) {
+      res.status (http.status_bad_request);
+      res.end ('invalid json input');
+    }
+    return null;
+  }
+
+  protected ensure_data (
+    data: object,
+    res: Response,
+    fail_on_undef = true
+  ): Promise<object>|object {
+    const obj = {};
+    const keys = Object.keys (data);
+    for (const col of this.columns) {
+      if (!keys.includes (col) && fail_on_undef) {
+        res.status (http.status_bad_request)
+          .end (`missing field: ${col}`);
+        return null;
+      }
+      obj[col] = data[col];
+    }
+    for (const col of this.options.optional_columns)
+      obj[col] = data[col];
+
+    return obj;
   }
 
   public async create (req: Request, res: Response): Promise<void> {
-    if (!await this.call_auth (this.options.create_authentication, req, res))
+    if (!await this.options.create_authorization (req, res))
-      return;
-    if (!await this.call_auth (this.options.create_authorization, req, res))
       return;
 
     const body_data = await this.validate_body (req, res);
     if (body_data === null)
       return;
+
+    const db_data = await this.ensure_data (body_data, res);
+    if (db_data === null)
+      return;
+
+    const inserted = await this.knex (this.table)
+      .returning ('id')
+      .insert (db_data);
+
+    res.status (http.status_created)
+      .end (inserted[0]);
   }
 
   public async read (req: Request, res: Response): Promise<void> {
+    if (!await this.options.read_authorization (req, res))
+      return;
 
+    if (typeof req.headers.id === 'undefined') {
+      res.status (http.status_bad_request)
+        .end ('id undefined');
+      return;
+    }
+
+    const json = await this.knex (this.table)
+      .select ([
+        'id',
+        ...this.columns
+      ])
+      .where ({ id: req.headers.id });
+
+    res.status (json.length > 0 ? http.status_ok : http.status_not_found)
+      .json (json[0]);
   }
 
   public async update (req: Request, res: Response): Promise<void> {
+    if (!await this.options.update_authorization (req, res))
+      return;
 
+    const body_data = await this.validate_body (req, res);
+    if (body_data === null)
+      return;
+
+    const db_data = await this.ensure_data (body_data, res, false);
+    if (db_data === null)
+      return;
+
+    if (typeof req.headers.id === 'undefined') {
+      res.status (http.status_bad_request)
+        .end ('id undefined');
+      return;
+    }
+
+    await this.knex (this.table)
+      .where ({ id: req.headers.id })
+      .update (db_data);
+
+    res.status (http.status_ok)
+      .end (inserted[0]);
   }
 
   public async delete (req: Request, res: Response): Promise<void> {
+    if (!await this.options.delete_authorization (req, res))
+      return;
 
+    if (typeof req.headers.id === 'undefined') {
+      res.status (http.status_bad_request)
+        .end ('id undefined');
+      return;
+    }
+
+    await this.knex (this.table)
+      .where ({ id: req.headers.id })
+      .delete ();
+
+    res.status (http.status_ok)
+      .end ();
+  }
+
+  protected async create_or_update (
+    req: Request,
+    res: Response
+  ): Promise<void> {
+    if (typeof req.headers.id === 'undefined')
+      await this.create (req, res);
+    else
+      await this.update (req, res);
+  }
+
+  public register_handlers (router: Router): void {
+    router.post ('/', this.create_or_update);
+    router.get ('/', this.read);
+    router.delete ('/', this.delete);
   }
 }

lib/KnexCrudOptions.ts

@@ -1,25 +1,88 @@
 import { Request, Response } from 'express';
 
-type Authentication = {
-  (req: Request, res: Response, next: Function);
-  (req: Request, res: Response): Promise<boolean>;
-}
-
 type Authorization = {
   (req: Request, res: Response, next: Function);
   (req: Request, res: Response): Promise<boolean>;
 }
 
-export class KnexCrudOptions {
+type AuthRunner = {
-  public create_authentication?: Authentication;
+  (req: Request, res: Response): Promise<boolean>;
-  public read_authentication?: Authentication;
+}
-  public update_authentication?: Authentication;
-  public delete_authentication?: Authentication;
 
-  public create_authorization?: Authorization;
+export class KnexCrudOptions {
-  public read_authorization?: Authorization;
+  private _general_authorization?: Authorization;
-  public update_authorization?: Authorization;
+  private _create_authorization?: Authorization;
-  public delete_authorization?: Authorization;
+  private _read_authorization?: Authorization;
+  private _update_authorization?: Authorization;
+  private _delete_authorization?: Authorization;
 
   public optional_columns?: Array<string>;
+
+  private get_auth_runner (
+    auth?: Authorization
+  ): AuthRunner {
+    if (typeof auth === 'undefined')
+      return (): Promise<boolean> => new Promise ((r) => r (true));
+    return (): Promise<boolean> => new Promise ((resolve) => {
+      const result = auth (req, res, resolve);
+      if (typeof result !== 'undefined')
+        resolve (result);
+    });
+  }
+
+  public set general_authorization (value: Authorization): void{
+    this._general_authorization = value;
+  }
+
+  public get create_authorization (): AuthRunner {
+    const general = this.get_auth_runner (this._general_authorization);
+    const specific = this.get_auth_runner (this._create_authorization);
+    return async (req, res): Promise<boolean> => {
+      const res = (await general (req, res)) && (await specific (req, res));
+      return res;
+    };
+  }
+
+  public set create_authorization (value: Authorization): void{
+    this._create_authorization = value;
+  }
+
+  public get read_authorization (): AuthRunner {
+    const general = this.get_auth_runner (this._general_authorization);
+    const specific = this.get_auth_runner (this._read_authorization);
+    return async (req, res): Promise<boolean> => {
+      const res = (await general (req, res)) && (await specific (req, res));
+      return res;
+    };
+  }
+
+  public set read_authorization (value: Authorization): void{
+    this._read_authorization = value;
+  }
+
+  public get update_authorization (): AuthRunner {
+    const general = this.get_auth_runner (this._general_authorization);
+    const specific = this.get_auth_runner (this._update_authorization);
+    return async (req, res): Promise<boolean> => {
+      const res = (await general (req, res)) && (await specific (req, res));
+      return res;
+    };
+  }
+
+  public set update_authorization (value: Authorization): void{
+    this._update_authorization = value;
+  }
+
+  public get delete_authorization (): AuthRunner {
+    const general = this.get_auth_runner (this._general_authorization);
+    const specific = this.get_auth_runner (this._delete_authorization);
+    return async (req, res): Promise<boolean> => {
+      const res = (await general (req, res)) && (await specific (req, res));
+      return res;
+    };
+  }
+
+  public set delete_authorization (value: Authorization): void{
+    this._delete_authorization = value;
+  }
 }

lib/KnexInterface.ts

@@ -0,0 +1,31 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+
+interface KnexQuery {
+  insert(data: object): Promise;
+  update(data: object): Promise;
+  select(...columns: Array<string>): Promise;
+  delete(): Promise;
+  where(filter: object): KnexQuery;
+  whereNot(filter: object): KnexQuery;
+  whereIn(filter: object): KnexQuery;
+  whereNotIn(filter: object): KnexQuery;
+  whereNull(filter: object): KnexQuery;
+  whereNotNull(filter: object): KnexQuery;
+  whereExists(filter: object): KnexQuery;
+  whereNotExists(filter: object): KnexQuery;
+  whereBetween(filter: object): KnexQuery;
+  whereNotBetween(filter: object): KnexQuery;
+  join(table: string, col: string, on: string): KnexQuery;
+  leftJoin(table: string, col: string, on: string): KnexQuery;
+  rightJoin(table: string, col: string, on: string): KnexQuery;
+  leftOuterJoin(table: string, col: string, on: string): KnexQuery;
+  rightOuterJoin(table: string, col: string, on: string): KnexQuery;
+  fullOuterJoin(table: string, col: string, on: string): KnexQuery;
+  returning(column: string | Array<string>): KnexQuery;
+}
+
+type Knex = {
+  (table: string): KnexQuery;
+}
+
+export { Knex, KnexQuery };

package.json

@@ -29,7 +29,6 @@
   },
   "dependencies": {
     "@scode/consts": "^1.1.4",
-    "@scode/utilities": "^1.0.21",
     "@types/express": "^4.17.6",
     "express": "^4.17.1"
   }

yarn.lock

@@ -155,11 +155,6 @@
     eslint-plugin-node "^11.0.0"
     eslint-plugin-sort-requires-by-path "^1.0.2"
 
-"@scode/utilities@^1.0.21":
-  version "1.0.21"
-  resolved "https://npm.scode.ovh/@scode%2futilities/-/utilities-1.0.21.tgz#adbc50720515df16fc05bc97b56cb9ba35499e0a"
-  integrity sha512-2F5mSTN7/2w5YQgamp2nan6q75Nln6bjAVBOvTrrQMbhWkZnieKzgt3g9M8GnsICVefmk5IPguiZhWPVYLmQxw==
-
 "@stryker-mutator/api@^3.1.0":
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/@stryker-mutator/api/-/api-3.1.0.tgz#7eb6f1e1f2af17ff0425c6aa0d4d244ca822e972"