diff --git a/CHANGELOG.md b/CHANGELOG.md
index f404827..748c0f5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Change log
 
+## 3.7.0 (2025-01-07)
+
+- fix: cast falsy values `false`, `null`, `undefined`, `NaN` to a string.
+  In previous versions, the empty string `''` was returned for falsy values.
+- fix: functions with argument `0` , e.g. `ansis.red(0)`, returning empty string `''`, now return colored value `'0'`
+- test: add tests for function arguments with various types
+
 ## 3.6.0 (2025-01-04)
 
 - feat: remove **undocumented** pointless dummy function `ansis(any)`
diff --git a/README.md b/README.md
index d787626..4648694 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@
 
 A [small](#compare-size) and [fast](#benchmark) Node.js library for applying ANSI colors and styles in terminal output.\
 Ansis provides all the [features](#features) you need, you can compare with [similar libraries](#compare).\
-Ansis is [faster](#benchmark) than **Chalk** and **Picocolors** (in some use cases), see [benchmarks](#benchmark).
+Ansis is as [small](#compare-size) as **Picocolors** but has the [functionality](#compare) of **Chalk**.
 
 
 ### 🚀 [Install and Quick Start](#install) 🔄 [Why switch to Ansis](#why-switch-to-ansis)
diff --git a/bench/index.js b/bench/index.js
index bce2b2a..8b87f3c 100644
--- a/bench/index.js
+++ b/bench/index.js
@@ -140,8 +140,8 @@ bench('Chained syntax').
   // kolorist - (not supported)
   run();
 
-// Nested styles, like picocolors recursion
-bench('Nested styles').
+// Nested calls, like colorette recursion
+bench('Nested calls').
   add(packages['chalk'], () => chalk.red(chalk.bold(chalk.underline(chalk.bgWhite('foo'))))).
   add(packages['ansis'], () => ansis.red(ansis.bold(ansis.underline(ansis.bgWhite('foo'))))).
   add(packages['picocolors'], () => picocolors.red(picocolors.bold(picocolors.underline(picocolors.bgWhite('foo'))))).
diff --git a/package.json b/package.json
index 87b8ff2..223f15f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ansis",
-  "version": "3.6.0",
+  "version": "3.7.0",
   "description": "A small and fast Node.js library for applying ANSI colors and styles in terminal output",
   "keywords": [
     "ansi",
diff --git a/package.npm.json b/package.npm.json
index fda4689..a1ceb1d 100644
--- a/package.npm.json
+++ b/package.npm.json
@@ -1,6 +1,6 @@
 {
   "name": "ansis",
-  "version": "3.6.0",
+  "version": "3.7.0",
   "description": "ANSI colors and styles in terminal output",
   "keywords": [
     "ansi",
diff --git a/src/index.js b/src/index.js
index 34d024e..a3518b8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -35,15 +35,14 @@ let createStyle = ({ _p: props }, { open, close }) => {
    * @return {string}
    */
   let styleFn = (strings, ...values) => {
-    if (!strings) return '';
-
     let props = styleFn._p;
     let { _a: openStack, _b: closeStack } = props;
 
-    let str = strings.raw
+    // optional chaining operator `?.` available since node >= 14
+    let str = strings?.raw
       // render template strings
       ? String.raw(strings, ...values)
-      // convert the number to the string
+      // convert the value to a string
       : '' + strings;
 
     // -> detect nested styles
diff --git a/test/ansi16.test.js b/test/ansi16.test.js
index 36febc4..9f70895 100644
--- a/test/ansi16.test.js
+++ b/test/ansi16.test.js
@@ -2,7 +2,7 @@ import { expect, describe, test } from 'vitest';
 import { esc } from './utils/helpers.js';
 
 // import env variables to simulate ANSI 16 color space
-import './env/color-space.ansi16.js';
+import './env/ansi16-colors.js';
 
 //import { hex, green } from '../src/index.mjs'; // for debugging only
 import { hex, green } from 'ansis';
diff --git a/test/ansi256.test.js b/test/ansi256.test.js
index efd6c8f..c36e7e8 100644
--- a/test/ansi256.test.js
+++ b/test/ansi256.test.js
@@ -2,7 +2,7 @@ import { expect, describe, test } from 'vitest';
 import { esc } from './utils/helpers.js';
 
 // import env variables to simulate ANSI 256 color space
-import './env/color-space.ansi256.js';
+import './env/ansi256-colors.js';
 
 //import { hex, ansi256 } from '../src/index.mjs'; // for debugging only
 import { hex, ansi256 } from 'ansis';
diff --git a/test/env/color-space.ansi16.js b/test/env/ansi16-colors.js
similarity index 100%
rename from test/env/color-space.ansi16.js
rename to test/env/ansi16-colors.js
diff --git a/test/env/color-space.ansi256.js b/test/env/ansi256-colors.js
similarity index 100%
rename from test/env/color-space.ansi256.js
rename to test/env/ansi256-colors.js
diff --git a/test/env/color-space.mono.js b/test/env/mono-color.js
similarity index 100%
rename from test/env/color-space.mono.js
rename to test/env/mono-color.js
diff --git a/test/env/color-space.truecolor.js b/test/env/truecolor.js
similarity index 100%
rename from test/env/color-space.truecolor.js
rename to test/env/truecolor.js
diff --git a/test/flags.test.js b/test/flags.test.js
index a739d8a..2ade360 100644
--- a/test/flags.test.js
+++ b/test/flags.test.js
@@ -3,7 +3,7 @@ import { expect, describe, test } from 'vitest';
 import { esc, execScriptSync } from './utils/helpers.js';
 
 // import env variables to simulate truecolor color space in CLI
-import './env/color-space.truecolor.js';
+import './env/truecolor.js';
 
 const TEST_PATH = path.resolve('./test/');
 
diff --git a/test/functional.test.js b/test/functional.test.js
index a66fff5..705b5e7 100644
--- a/test/functional.test.js
+++ b/test/functional.test.js
@@ -2,7 +2,7 @@ import { describe, test, expect } from 'vitest';
 import { esc } from './utils/helpers.js';
 
 // import env variables to simulate truecolor color space in CLI
-import './env/color-space.truecolor.js';
+import './env/truecolor.js';
 
 //import ansis, { Ansis, red, yellow, green, bold, hex } from '../src/index.mjs'; //  // for debugging only
 import ansis, { Ansis, red, grey, gray, green, yellow, bold, italic, underline, hex } from 'ansis'; // test npm package
@@ -15,6 +15,182 @@ describe('support colors', () => {
   });
 });
 
+describe('convert function argument to string', () => {
+  test(`no argument`, () => {
+    // if no argument is provided, an empty string w/o escape codes should be returned,
+    // but this is such an incredible case that we won't check it,
+    // we cast no argument as `undefined`,
+    // picocolors doesn't check this edge case either
+    const received = ansis.green();
+    const expected = '\x1b[32mundefined\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`empty string`, () => {
+    // if argument is empty string, an empty string w/o escape codes should be returned,
+    // but this is such an incredible case that we won't check it,
+    // picocolors doesn't check this edge case either
+    const received = ansis.green('');
+    const expected = '\x1b[32m\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`string`, () => {
+    const received = ansis.green('green');
+    const expected = '\x1b[32mgreen\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`number`, () => {
+    const received = ansis.green(1974);
+    const expected = '\x1b[32m1974\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`number with separator`, () => {
+    const received = ansis.green(999_55);
+    const expected = '\x1b[32m99955\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`float`, () => {
+    const received = ansis.green(999.55);
+    const expected = '\x1b[32m999.55\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`true`, () => {
+    const received = ansis.green(true);
+    const expected = '\x1b[32mtrue\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  // fixed in v3.7.0
+  test(`false`, () => {
+    const received = ansis.green(false);
+    const expected = '\x1b[32mfalse\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  // fixed in v3.7.0
+  test(`falsy value 0`, () => {
+    const received = ansis.green(0);
+    const expected = '\x1b[32m0\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  // fixed in v3.7.0
+  test(`null`, () => {
+    const received = ansis.green(null);
+    const expected = '\x1b[32mnull\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  // fixed in v3.7.0
+  test(`undefined`, () => {
+    const received = ansis.green(undefined);
+    const expected = '\x1b[32mundefined\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  // fixed in v3.7.0
+  test(`NaN`, () => {
+    const received = ansis.green(NaN);
+    const expected = '\x1b[32mNaN\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`Infinity`, () => {
+    const received = ansis.green(Infinity);
+    const expected = '\x1b[32mInfinity\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`Array<number>`, () => {
+    const received = ansis.green([999, 55]);
+    const expected = '\x1b[32m999,55\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`Array<string>`, () => {
+    const received = ansis.green(['Hello', 'world']);
+    const expected = '\x1b[32mHello,world\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`Set<string>`, () => {
+    const set = new Set(['Hello', 'world']);
+    const received = ansis.green([...set]);
+    const expected = '\x1b[32mHello,world\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+});
+
+describe('arguments in template string', () => {
+  test(`falsy value 0 in template`, () => {
+    const received = ansis.green(`zero ${0} value`);
+    const expected = '\x1b[32mzero 0 value\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+
+  test(`null in template`, () => {
+    const received = ansis.green(`${null} value`);
+    const expected = '\x1b[32mnull value\x1b[39m';
+    expect(received).toEqual(expected);
+  });
+});
+
+describe('handling numbers', () => {
+  test(`ansis.bold(123)`, () => {
+    const num = 123;
+    const received = ansis.bold(num);
+    const expected = '\x1b[1m123\x1b[22m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`ansis.red(123)`, () => {
+    const num = 123;
+    const received = ansis.red(num);
+    const expected = '\x1b[31m123\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`red(123)`, () => {
+    const num = 123;
+    const received = red(num);
+    const expected = '\x1b[31m123\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`bold(123)`, () => {
+    const num = 123;
+    const received = bold(num);
+    const expected = '\x1b[1m123\x1b[22m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`red.bold(123)`, () => {
+    const num = 123;
+    const received = red.bold(num);
+    const expected = '\x1b[31m\x1b[1m123\x1b[22m\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`hex('#A00')(123)`, () => {
+    const num = 123;
+    const received = hex('#A00')(num);
+    const expected = '\x1b[38;2;170;0;0m123\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test('red`size: ${123}px`', () => {
+    const num = 123;
+    const received = red`size: ${num}px`;
+    const expected = '\x1b[31msize: 123px\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+});
+
 describe('style tests', () => {
   test(`ansis.visible('foo')`, () => {
     const received = ansis.visible('foo');
@@ -28,12 +204,6 @@ describe('style tests', () => {
     expect(esc(received)).toEqual(esc(expected));
   });
 
-  test(`ansis.green('')`, () => {
-    const received = ansis.green('');
-    const expected = '';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
   test(`ansis.green('foo', 'bar')`, () => {
     const received = ansis.green(['foo', 'bar'].join(' '));
     const expected = '\x1b[32mfoo bar\x1b[39m';
@@ -88,16 +258,6 @@ describe('style tests', () => {
     expect(esc(received)).toEqual(esc(expected));
   });
 
-  test(`ansis.green('\nHello\nNew line\nNext new line.\n')`, () => {
-    const received = ansis.green('\nHello\nNew line\nNext new line.\n');
-    const expected = `\x1b[32m\x1b[39m
-\x1b[32mHello\x1b[39m
-\x1b[32mNew line\x1b[39m
-\x1b[32mNext new line.\x1b[39m
-\x1b[32m\x1b[39m`;
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
   // experimental link: not widely supported
   // test(`ansis.link('foo')`, () => {
   //   const received = ansis.link('https://github.com/webdiscus/ansis')('foo');
@@ -106,6 +266,37 @@ describe('style tests', () => {
   // });
 });
 
+describe('style new line', () => {
+  test(`linux new line LF`, () => {
+    const received = ansis.green('Hello\nWorld');
+    const expected = '\x1b[32mHello\x1b[39m\n\x1b[32mWorld\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`windows new line CRLF`, () => {
+    const received = ansis.green('Hello\r\nWorld');
+    const expected = '\x1b[32mHello\x1b[39m\r\n\x1b[32mWorld\x1b[39m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`linux new line LF, background`, () => {
+    const received = ansis.bgGreen(' Hello \n World ');
+    const expected = '\x1b[42m Hello \x1b[49m\n\x1b[42m World \x1b[49m';
+    expect(esc(received)).toEqual(esc(expected));
+  });
+
+  test(`multiple new line`, () => {
+    const received = ansis.bgGreen('\nHello\nNew line\nNext new line.\n');
+    const expected = `\x1b[42m\x1b[49m
+\x1b[42mHello\x1b[49m
+\x1b[42mNew line\x1b[49m
+\x1b[42mNext new line.\x1b[49m
+\x1b[42m\x1b[49m`;
+    console.log(received);
+    expect(esc(received)).toEqual(esc(expected));
+  });
+});
+
 describe('advanced features tests', () => {
   test(`nested styles`, () => {
     const received = ansis.red('foo' + ansis.underline.bgBlue('bar') + '!');
@@ -194,6 +385,16 @@ describe('alias tests', () => {
     const expected = '\x1b[38;5;96m\x1b[38;5;96mfoo\x1b[39m\x1b[39m';
     expect(esc(received)).toEqual(esc(expected));
   });
+
+  test(`caching of aliases`, () => {
+    const {gray, grey} = ansis.gray;
+    const grayBold = gray.bold.italic;
+    const greyBold = grey.bold.underline;
+
+    expect(gray('foo')).toBe(grey('foo'));
+    expect(grayBold('bar')).not.toBe(greyBold('bar'));
+    expect(grey('baz')).not.toBe(greyBold('baz'));
+  });
 });
 
 describe('template literals tests', () => {
@@ -247,57 +448,6 @@ describe('extend base colors tests', () => {
   });
 });
 
-describe('handling numbers', () => {
-  test(`ansis.bold(123)`, () => {
-    const num = 123;
-    const received = ansis.bold(num);
-    const expected = '\x1b[1m123\x1b[22m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test(`ansis.red(123)`, () => {
-    const num = 123;
-    const received = ansis.red(num);
-    const expected = '\x1b[31m123\x1b[39m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test(`red(123)`, () => {
-    const num = 123;
-    const received = red(num);
-    const expected = '\x1b[31m123\x1b[39m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test(`bold(123)`, () => {
-    const num = 123;
-    const received = bold(num);
-    const expected = '\x1b[1m123\x1b[22m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test(`red.bold(123)`, () => {
-    const num = 123;
-    const received = red.bold(num);
-    const expected = '\x1b[31m\x1b[1m123\x1b[22m\x1b[39m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test(`hex('#A00')(123)`, () => {
-    const num = 123;
-    const received = hex('#A00')(num);
-    const expected = '\x1b[38;2;170;0;0m123\x1b[39m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-
-  test('red`size: ${123}px`', () => {
-    const num = 123;
-    const received = red`size: ${num}px`;
-    const expected = '\x1b[31msize: 123px\x1b[39m';
-    expect(esc(received)).toEqual(esc(expected));
-  });
-});
-
 describe('base ANSI 16 colors', () => {
   // foreground colors
   test(`ansis.black('foo')`, () => {
diff --git a/test/no-color.test.js b/test/no-color.test.js
index 8449513..7850955 100644
--- a/test/no-color.test.js
+++ b/test/no-color.test.js
@@ -1,7 +1,7 @@
 import { expect, describe, test } from 'vitest';
 
 // import env variables to simulate no color
-import './env/color-space.mono.js';
+import './env/mono-color.js';
 
 //import ansis, { red } from '../src/index.mjs'; // for debugging only
 import ansis, { red } from 'ansis';
diff --git a/test/package.test.js b/test/package.test.js
index 93eb1fa..3b114c2 100644
--- a/test/package.test.js
+++ b/test/package.test.js
@@ -3,7 +3,7 @@ import { expect, describe, test } from 'vitest';
 import { esc, execScriptSync } from './utils/helpers.js';
 
 // import env variables to simulate truecolor color space in CLI
-import './env/color-space.truecolor.js';
+import './env/truecolor.js';
 
 const TEST_PATH = path.resolve('./test/');
 
diff --git a/test/ts-compiler.test.js b/test/ts-compiler.test.js
index 4f6500b..72699ac 100644
--- a/test/ts-compiler.test.js
+++ b/test/ts-compiler.test.js
@@ -2,7 +2,7 @@ import { describe, test } from 'vitest';
 import { executeTSFile } from './utils/helpers.js';
 
 // import env variables to simulate truecolor color space in CLI
-import './env/color-space.truecolor.js';
+import './env/truecolor.js';
 
 // integration tests: compile TS into JS, execute compiled JS and compare the output with expected string
 describe('imports', () => {