refactoring

lib/Types/PathType.ts

@@ -0,0 +1,23 @@
+import fs from 'fs-extra';
+import { TypeValidation } from './TypeValidation';
+
+export class PathType extends TypeValidation {
+  public get string_type (): 'string'|'number'|'boolean'|'array' {
+    return 'string';
+  }
+
+  public async to_type (value: unknown): Promise<unknown> {
+    if (typeof value !== 'string')
+      throw new Error (`invalid type for ${this.general_type}`);
+    if (!await fs.pathExists (value))
+      throw new Error ('path does not exist');
+    if (this.general_type === 'path')
+      return value;
+
+    const stat = await fs.stat (value);
+    if (stat.isDirectory () === (this.general_type === 'folder'))
+      return value;
+
+    throw new Error ('cannot assign folder to file');
+  }
+}

lib/Types/TypeValidation.ts

@@ -0,0 +1,44 @@
+export class TypeValidation {
+  private readonly _general_type: string;
+
+  public get general_type (): string {
+    return this._general_type;
+  }
+
+  public get string_type (): 'string'|'number'|'boolean'|'array' {
+    return this._general_type as 'string'|'number'|'boolean'|'array';
+  }
+
+  public constructor (type: string) {
+    this._general_type = type;
+  }
+
+  public validate_type (value: unknown): boolean {
+    return typeof value === this.general_type;
+  }
+
+  public to_type (value: unknown): Promise<unknown> {
+    if (this.general_type === 'string')
+      return Promise.resolve (String (value));
+
+    if (this.general_type === 'number') {
+      const as_num = parseInt (String (value));
+      if (isNaN (as_num))
+        throw new Error ('value is not a number');
+      return Promise.resolve (as_num);
+    }
+
+    if (this.general_type === 'boolean') {
+      const as_num = parseInt (String (value));
+      if (
+        as_num !== 1 && as_num !== 0
+        && !(/^(?:true|false)$/iu).test (String (value))
+      )
+        throw new Error ('value is not a boolean');
+      return Promise.resolve (
+        as_num === 1 || (/true/iu).test (String (value))
+      );
+    }
+    throw new Error ('unknown type');
+  }
+}