feat(packages/stdlib): start getByPath and template tools

packages/stdlib/src/text/index.ts

@@ -1,2 +1,3 @@
 export * from './levenshtein-distance';
-export * from './trigram-distance';
+export * from './trigram-distance';
+export * from './template';

packages/stdlib/src/text/template/index.test-d.ts

@@ -0,0 +1,105 @@
+import { describe, expectTypeOf, it } from "vitest";
+import type { ClearPlaceholder, ExtractPlaceholders } from "./index";
+
+describe('template', () => {
+  describe('ClearPlaceholder', () => {
+    it('ignores strings without braces', () => {
+      type actual = ClearPlaceholder<'name'>;
+      type expected = 'name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('removes all balanced braces from placeholders', () => {
+      type actual1 = ClearPlaceholder<'{name}'>;
+      type actual2 = ClearPlaceholder<'{{name}}'>;
+      type actual3 = ClearPlaceholder<'{{{name}}}'>;
+      type expected = 'name';
+
+      expectTypeOf<actual1>().toEqualTypeOf<expected>();
+      expectTypeOf<actual2>().toEqualTypeOf<expected>();
+      expectTypeOf<actual3>().toEqualTypeOf<expected>();
+    });
+
+    it('removes all unbalanced braces from placeholders', () => {
+      type actual1 = ClearPlaceholder<'{name}}'>;
+      type actual2 = ClearPlaceholder<'{{name}}}'>;
+      type expected = 'name';
+
+      expectTypeOf<actual1>().toEqualTypeOf<expected>();
+      expectTypeOf<actual2>().toEqualTypeOf<expected>();
+    });
+  });
+
+  describe('ExtractPlaceholders', () => {
+    it('string without placeholders', () => {
+      type actual = ExtractPlaceholders<'Hello name, how are?'>;
+      type expected = never;
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with one idexed placeholder', () => {
+      type actual = ExtractPlaceholders<'Hello {0}, how are you?'>;
+      type expected = '0';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with two indexed placeholders', () => {
+      type actual = ExtractPlaceholders<'Hello {0}, my name is {1}'>;
+      type expected = '0' | '1';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with one key placeholder', () => {
+      type actual = ExtractPlaceholders<'Hello {name}, how are you?'>;
+      type expected = 'name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with two key placeholders', () => {
+      type actual = ExtractPlaceholders<'Hello {name}, my name is {managers.0.name}'>;
+      type expected = 'name' | 'managers.0.name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with mixed placeholders', () => {
+      type actual = ExtractPlaceholders<'Hello {0}, how are you? My name is {1.name}'>;
+      type expected = '0' | '1.name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with nested placeholder and balanced braces', () => {
+      type actual = ExtractPlaceholders<'Hello {{name}}, how are you?'>;
+      type expected = 'name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with nested placeholder and unbalanced braces', () => {
+      type actual = ExtractPlaceholders<'Hello {{{name}, how are you?'>;
+      type expected = 'name';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with nested placeholders and balanced braces', () => {
+      type actual = ExtractPlaceholders<'Hello {{{name}{positions}}}, how are you?'>;
+      type expected = 'name' | 'positions';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+
+    it('string with nested placeholders and unbalanced braces', () => {
+      type actual = ExtractPlaceholders<'Hello {{{name}{positions}, how are you?'>;
+      type expected = 'name' | 'positions';
+
+      expectTypeOf<actual>().toEqualTypeOf<expected>();
+    });
+  });
+});

packages/stdlib/src/text/template/index.test.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from 'vitest';
+import { templateObject } from './index';
+
+describe('templateObject', () => {
+  // it('replace template placeholders with corresponding values from args', () => {
+  //   const template = 'Hello, {names.0}!';
+  //   const args = { names: ['John'] };
+  //   const result = templateObject(template, args);
+  //   expect(result).toBe('Hello, John!');
+  // });
+
+  // it('replace template placeholders with corresponding values from args', () => {
+  //   const template = 'Hello, {name}!';
+  //   const args = { name: 'John' };
+  //   const result = templateObject(template, args);
+  //   expect(result).toBe('Hello, John!');
+  // });
+
+  // it('replace template placeholders with fallback value if corresponding value is undefined', () => {
+  //   const template = 'Hello, {name}!';
+  //   const args = { age: 25 };
+  //   const fallback = 'Guest';
+  //   const result = templateObject(template, args, fallback);
+  //   expect(result).toBe('Hello, Guest!');
+  // });
+
+  // it(' replace template placeholders with fallback value returned by fallback function if corresponding value is undefined', () => {
+  //   const template = 'Hello, {name}!';
+  //   const args = { age: 25 };
+  //   const fallback = (key: string) => `Unknown ${key}`;
+  //   const result = templateObject(template, args, fallback);
+  //   expect(result).toBe('Hello, Unknown name!');
+  // });
+
+  it('replace template placeholders with nested values from args', () => {
+      const template = 'Hello, {user.name}!';
+      const args = { user: { name: 'John' } };
+      const result = templateObject(template, args);
+
+      expect(result).toBe('Hello, John!');
+  });
+});

packages/stdlib/src/text/template/index.ts

@@ -0,0 +1,52 @@
+import { getByPath, type Generate } from '../../arrays';
+
+/**
+ * Type of a value that will be used to replace a placeholder in a template.
+ */
+type StringPrimitive = string | number | bigint | null | undefined;
+
+/**
+ * Type of a fallback value when a template key is not found.
+ */
+type TemplateFallback = string | ((key: string) => string);
+
+/**
+ * Type of an object that will be used to replace placeholders in a template.
+ */
+type TemplateArgsObject = StringPrimitive[] | { [key: string]: TemplateArgsObject | StringPrimitive };
+
+/**
+ * Type of a template string with placeholders.
+ */
+const TEMPLATE_PLACEHOLDER = /{([^{}]+)}/gm;
+
+export type ClearPlaceholder<T extends string> =
+  T extends `${string}{${infer Template}`
+    ? ClearPlaceholder<Template>
+    : T extends `${infer Template}}${string}`
+      ? ClearPlaceholder<Template>
+      : T;
+
+export type ExtractPlaceholders<T extends string> =
+  T extends `${infer Before}}${infer After}`
+    ? Before extends `${string}{${infer Placeholder}`
+      ? ClearPlaceholder<Placeholder> | ExtractPlaceholders<After>
+      : ExtractPlaceholders<After>
+    : never;
+
+export function templateObject<T extends string, A extends Generate<ExtractPlaceholders<T>>>(template: T, args: A, fallback?: TemplateFallback): string {
+    return template.replace(TEMPLATE_PLACEHOLDER, (subs, key) => {
+        return getByPath(args, key) as string;
+        // return value !== undefined ? value : (isFunction(fallback) ? fallback(key) : fallback);
+    });
+}
+
+templateObject('Hello {user.name}, your address {user.addresses.0}', {
+   user: {
+    name: 'John Doe',
+    addresses: [
+      { street: '123 Main St', city: 'Springfield'},
+      { street: '456 Elm St', city: 'Shelbyville'}
+    ]
+  }
+});