feat: Add Bool scalar (#17)

Part of #6

Author: erezrokah

package-lock.json

@@ -71,6 +71,7 @@
   "dependencies": {
     "@apache-arrow/esnext-esm": "^12.0.1",
     "@cloudquery/plugin-pb-javascript": "^0.0.6",
+    "boolean": "^3.2.0",
     "yargs": "^17.7.2"
   }
 }

package.json

@@ -0,0 +1,35 @@
+import test from 'ava';
+import { DataType } from '@apache-arrow/esnext-esm';
+import { Bool } from './bool.js';
+
+[null, undefined].forEach((v) => {
+  test(`should set values to false when ${v} is passed`, (t) => {
+    const b = new Bool(v);
+    t.is(b.Valid, false);
+    t.true(DataType.isBool(b.DataType));
+  });
+});
+
+[1, true, 'true', 'Y', 'y', 'TRUE', 'on', new Bool(true)].forEach((v, i) => {
+  test(`should support truthy value '${v}' (${i})`, (t) => {
+    const b = new Bool(v);
+    t.is(b.Valid, true);
+    t.is(b.Value, true);
+    t.true(DataType.isBool(b.DataType));
+    t.is(b.toString(), 'true');
+  });
+});
+
+[0, false, 'false', 'N', 'n', 'FALSE', 'off', new Bool(false)].forEach((v, i) => {
+  test(`should support falsy value '${v}' (${i})`, (t) => {
+    const b = new Bool(v);
+    t.is(b.Valid, true);
+    t.is(b.Value, false);
+    t.true(DataType.isBool(b.DataType));
+    t.is(b.toString(), 'false');
+  });
+});
+
+test('should throw when unable to set value', (t) => {
+  t.throws(() => new Bool({ value: {} }), { message: "Unable to set '[object Object]' as Bool" });
+});

src/scalar/bool.test.ts

@@ -0,0 +1,54 @@
+import { Bool as ArrowBool } from '@apache-arrow/esnext-esm';
+import { boolean, isBooleanable } from 'boolean';
+import { isInvalid, NULL_VALUE } from './util.js';
+
+export class Bool {
+  private _valid = false;
+  private _value = false;
+
+  public constructor(v: unknown) {
+    this.Valid = v;
+    return this;
+  }
+
+  public get DataType() {
+    return new ArrowBool();
+  }
+
+  public get Valid(): boolean {
+    return this._valid;
+  }
+
+  public get Value(): boolean {
+    return this._value;
+  }
+
+  public set Valid(value: unknown) {
+    if (isInvalid(value)) {
+      this._valid = false;
+      return;
+    }
+
+    if (value instanceof Bool) {
+      this._valid = value.Valid;
+      this._value = value.Value;
+      return;
+    }
+
+    if (isBooleanable(value)) {
+      this._value = boolean(value);
+      this._valid = true;
+      return;
+    }
+
+    throw new Error(`Unable to set '${value}' as Bool`);
+  }
+
+  public toString() {
+    if (this._valid) {
+      return String(this._value);
+    }
+
+    return NULL_VALUE;
+  }
+}

src/scalar/bool.ts

@@ -0,0 +1,3 @@
+export const NULL_VALUE = '(null)';
+
+export const isInvalid = (value: unknown) => value === null || value === undefined;