From e3e87366158c4d2a3aaebe65056372c416836d1b Mon Sep 17 00:00:00 2001
From: Tatsunori Uchino <tats.u@live.jp>
Date: Sun, 20 Oct 2024 10:57:43 +0900
Subject: [PATCH] Implement code points validator

---
 .../actions/codePoints/codePoints.test-d.ts   |  50 ++++++
 .../src/actions/codePoints/codePoints.test.ts | 121 ++++++++++++++
 library/src/actions/codePoints/codePoints.ts  | 128 ++++++++++++++
 library/src/actions/codePoints/index.ts       |   1 +
 library/src/actions/index.ts                  |   3 +
 library/src/actions/maxCodePoints/index.ts    |   1 +
 .../maxCodePoints/maxCodePoints.test-d.ts     |  50 ++++++
 .../maxCodePoints/maxCodePoints.test.ts       | 150 +++++++++++++++++
 .../actions/maxCodePoints/maxCodePoints.ts    | 134 +++++++++++++++
 library/src/actions/minCodePoints/index.ts    |   1 +
 .../minCodePoints/minCodePoints.test-d.ts     |  50 ++++++
 .../minCodePoints/minCodePoints.test.ts       | 157 ++++++++++++++++++
 .../actions/minCodePoints/minCodePoints.ts    | 134 +++++++++++++++
 .../_getCodePointCount.test.ts                |  16 ++
 .../_getCodePointCountCount.ts                |  23 +++
 library/src/utils/_getCodePointCount/index.ts |   1 +
 library/src/utils/index.ts                    |   1 +
 17 files changed, 1021 insertions(+)
 create mode 100644 library/src/actions/codePoints/codePoints.test-d.ts
 create mode 100644 library/src/actions/codePoints/codePoints.test.ts
 create mode 100644 library/src/actions/codePoints/codePoints.ts
 create mode 100644 library/src/actions/codePoints/index.ts
 create mode 100644 library/src/actions/maxCodePoints/index.ts
 create mode 100644 library/src/actions/maxCodePoints/maxCodePoints.test-d.ts
 create mode 100644 library/src/actions/maxCodePoints/maxCodePoints.test.ts
 create mode 100644 library/src/actions/maxCodePoints/maxCodePoints.ts
 create mode 100644 library/src/actions/minCodePoints/index.ts
 create mode 100644 library/src/actions/minCodePoints/minCodePoints.test-d.ts
 create mode 100644 library/src/actions/minCodePoints/minCodePoints.test.ts
 create mode 100644 library/src/actions/minCodePoints/minCodePoints.ts
 create mode 100644 library/src/utils/_getCodePointCount/_getCodePointCount.test.ts
 create mode 100644 library/src/utils/_getCodePointCount/_getCodePointCountCount.ts
 create mode 100644 library/src/utils/_getCodePointCount/index.ts

diff --git a/library/src/actions/codePoints/codePoints.test-d.ts b/library/src/actions/codePoints/codePoints.test-d.ts
new file mode 100644
index 000000000..819ac0c90
--- /dev/null
+++ b/library/src/actions/codePoints/codePoints.test-d.ts
@@ -0,0 +1,50 @@
+import { describe, expectTypeOf, test } from 'vitest';
+import type { InferInput, InferIssue, InferOutput } from '../../types/index.ts';
+import {
+  codePoints,
+  type CodePointsAction,
+  type CodePointsIssue,
+} from './codePoints.ts';
+
+describe('codePoints', () => {
+  describe('should return action object', () => {
+    test('with undefined message', () => {
+      type Action = CodePointsAction<string, 10, undefined>;
+      expectTypeOf(codePoints<string, 10>(10)).toEqualTypeOf<Action>();
+      expectTypeOf(
+        codePoints<string, 10, undefined>(10, undefined)
+      ).toEqualTypeOf<Action>();
+    });
+
+    test('with string message', () => {
+      expectTypeOf(
+        codePoints<string, 10, 'message'>(10, 'message')
+      ).toEqualTypeOf<CodePointsAction<string, 10, 'message'>>();
+    });
+
+    test('with function message', () => {
+      expectTypeOf(
+        codePoints<string, 10, () => string>(10, () => 'message')
+      ).toEqualTypeOf<CodePointsAction<string, 10, () => string>>();
+    });
+  });
+
+  describe('should infer correct types', () => {
+    type Input = 'example string';
+    type Action = CodePointsAction<Input, 5, undefined>;
+
+    test('of input', () => {
+      expectTypeOf<InferInput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of output', () => {
+      expectTypeOf<InferOutput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of issue', () => {
+      expectTypeOf<InferIssue<Action>>().toEqualTypeOf<
+        CodePointsIssue<Input, 5>
+      >();
+    });
+  });
+});
diff --git a/library/src/actions/codePoints/codePoints.test.ts b/library/src/actions/codePoints/codePoints.test.ts
new file mode 100644
index 000000000..9360d7f32
--- /dev/null
+++ b/library/src/actions/codePoints/codePoints.test.ts
@@ -0,0 +1,121 @@
+import { describe, expect, test } from 'vitest';
+import type { StringIssue } from '../../schemas/index.ts';
+import { _getCodePointCount } from '../../utils/index.ts';
+import { expectActionIssue, expectNoActionIssue } from '../../vitest/index.ts';
+import {
+  codePoints,
+  type CodePointsAction,
+  type CodePointsIssue,
+} from './codePoints.ts';
+
+describe('graphemes', () => {
+  describe('should return action object', () => {
+    const baseAction: Omit<CodePointsAction<string, 5, never>, 'message'> = {
+      kind: 'validation',
+      type: 'code_points',
+      reference: codePoints,
+      expects: '5',
+      requirement: 5,
+      async: false,
+      '~validate': expect.any(Function),
+    };
+
+    test('with undefined message', () => {
+      const action: CodePointsAction<string, 5, undefined> = {
+        ...baseAction,
+        message: undefined,
+      };
+      expect(codePoints(5)).toStrictEqual(action);
+      expect(codePoints(5, undefined)).toStrictEqual(action);
+    });
+
+    test('with string message', () => {
+      expect(codePoints(5, 'message')).toStrictEqual({
+        ...baseAction,
+        message: 'message',
+      } satisfies CodePointsAction<string, 5, string>);
+    });
+
+    test('with function message', () => {
+      const message = () => 'message';
+      expect(codePoints(5, message)).toStrictEqual({
+        ...baseAction,
+        message,
+      } satisfies CodePointsAction<string, 5, typeof message>);
+    });
+  });
+
+  describe('should return dataset without issues', () => {
+    const action = codePoints(5);
+
+    test('for untyped inputs', () => {
+      const issues: [StringIssue] = [
+        {
+          kind: 'schema',
+          type: 'string',
+          input: null,
+          expected: 'string',
+          received: 'null',
+          message: 'message',
+        },
+      ];
+      expect(
+        action['~validate']({ typed: false, value: null, issues }, {})
+      ).toStrictEqual({
+        typed: false,
+        value: null,
+        issues,
+      });
+    });
+
+    test('for valid strings', () => {
+      expectNoActionIssue(action, ['12345', '12 45', '1234 ', 'hello']);
+    });
+
+    test('for valid emoji', () => {
+      expectNoActionIssue(action, ['👨🏽‍👩🏽', '😶‍🌫️😀', '😡👍😁😂😀', '0️⃣㊙️']);
+    });
+
+    test('for valid non-latin', () => {
+      expectNoActionIssue(action, ['あ𛀙よろし', '𠮷野家で𩸽', '葛󠄀城市！']);
+    });
+  });
+
+  describe('should return dataset with issues', () => {
+    const action = codePoints(5, 'message');
+    const baseIssue: Omit<CodePointsIssue<string, 5>, 'input' | 'received'> = {
+      kind: 'validation',
+      type: 'code_points',
+      expected: '5',
+      message: 'message',
+      requirement: 5,
+    };
+
+    test('for invalid strings', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['', ' ', '1', '1234', '123 ', '123456', '12 456', '123456789'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid emoji', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['😀👋🏼🧩👩🏻‍🏫🫥', '㊙️㊙️0️⃣1️⃣2️⃣'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid non-latin', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['竈門禰󠄀豆子', '葛󠄀城市'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+  });
+});
diff --git a/library/src/actions/codePoints/codePoints.ts b/library/src/actions/codePoints/codePoints.ts
new file mode 100644
index 000000000..cb34c8f54
--- /dev/null
+++ b/library/src/actions/codePoints/codePoints.ts
@@ -0,0 +1,128 @@
+import type {
+  BaseIssue,
+  BaseValidation,
+  ErrorMessage,
+} from '../../types/index.ts';
+import { _addIssue, _getCodePointCount } from '../../utils/index.ts';
+
+/**
+ * CodePoints issue type.
+ */
+export interface CodePointsIssue<
+  TInput extends string,
+  TRequirement extends number,
+> extends BaseIssue<TInput> {
+  /**
+   * The issue kind.
+   */
+  readonly kind: 'validation';
+  /**
+   * The issue type.
+   */
+  readonly type: 'code_points';
+  /**
+   * The expected property.
+   */
+  readonly expected: `${TRequirement}`;
+  /**
+   * The received property.
+   */
+  readonly received: `${number}`;
+  /**
+   * The required codePoints.
+   */
+  readonly requirement: TRequirement;
+}
+
+/**
+ * CodePoints action type.
+ */
+export interface CodePointsAction<
+  TInput extends string,
+  TRequirement extends number,
+  TMessage extends
+    | ErrorMessage<CodePointsIssue<TInput, TRequirement>>
+    | undefined,
+> extends BaseValidation<TInput, TInput, CodePointsIssue<TInput, TRequirement>> {
+  /**
+   * The action type.
+   */
+  readonly type: 'code_points';
+  /**
+   * The action reference.
+   */
+  readonly reference: typeof codePoints;
+  /**
+   * The expected property.
+   */
+  readonly expects: `${TRequirement}`;
+  /**
+   * The required code points.
+   */
+  readonly requirement: TRequirement;
+  /**
+   * The error message.
+   */
+  readonly message: TMessage;
+}
+
+/**
+ * Creates a code points validation action.
+ *
+ * @param requirement The required code points.
+ *
+ * @returns A code points action.
+ */
+export function codePoints<
+  TInput extends string,
+  const TRequirement extends number,
+>(requirement: TRequirement): CodePointsAction<TInput, TRequirement, undefined>;
+
+/**
+ * Creates a code points validation action.
+ *
+ * @param requirement The required code points.
+ * @param message The error message.
+ *
+ * @returns A code points action.
+ */
+export function codePoints<
+  TInput extends string,
+  const TRequirement extends number,
+  const TMessage extends
+    | ErrorMessage<CodePointsIssue<TInput, TRequirement>>
+    | undefined,
+>(
+  requirement: TRequirement,
+  message: TMessage
+): CodePointsAction<TInput, TRequirement, TMessage>;
+
+export function codePoints(
+  requirement: number,
+  message?: ErrorMessage<CodePointsIssue<string, number>>
+): CodePointsAction<
+  string,
+  number,
+  ErrorMessage<CodePointsIssue<string, number>> | undefined
+> {
+  return {
+    kind: 'validation',
+    type: 'code_points',
+    reference: codePoints,
+    async: false,
+    expects: `${requirement}`,
+    requirement,
+    message,
+    '~validate'(dataset, config) {
+      if (dataset.typed) {
+        const count = _getCodePointCount(dataset.value);
+        if (count !== this.requirement) {
+          _addIssue(this, 'codePoints', dataset, config, {
+            received: `${count}`,
+          });
+        }
+      }
+      return dataset;
+    },
+  };
+}
diff --git a/library/src/actions/codePoints/index.ts b/library/src/actions/codePoints/index.ts
new file mode 100644
index 000000000..19100e9c5
--- /dev/null
+++ b/library/src/actions/codePoints/index.ts
@@ -0,0 +1 @@
+export * from './codePoints.ts';
diff --git a/library/src/actions/index.ts b/library/src/actions/index.ts
index 0c37dd5ca..4b6db015b 100644
--- a/library/src/actions/index.ts
+++ b/library/src/actions/index.ts
@@ -6,6 +6,7 @@ export * from './brand/index.ts';
 export * from './bytes/index.ts';
 export * from './check/index.ts';
 export * from './checkItems/index.ts';
+export * from './codePoints/index.ts';
 export * from './creditCard/index.ts';
 export * from './cuid2/index.ts';
 export * from './decimal/index.ts';
@@ -42,6 +43,7 @@ export * from './mac48/index.ts';
 export * from './mac64/index.ts';
 export * from './mapItems/index.ts';
 export * from './maxBytes/index.ts';
+export * from './maxCodePoints/index.ts';
 export * from './maxGraphemes/index.ts';
 export * from './maxLength/index.ts';
 export * from './maxSize/index.ts';
@@ -50,6 +52,7 @@ export * from './maxWords/index.ts';
 export * from './metadata/index.ts';
 export * from './mimeType/index.ts';
 export * from './minBytes/index.ts';
+export * from './minCodePoints/index.ts';
 export * from './minGraphemes/index.ts';
 export * from './minLength/index.ts';
 export * from './minSize/index.ts';
diff --git a/library/src/actions/maxCodePoints/index.ts b/library/src/actions/maxCodePoints/index.ts
new file mode 100644
index 000000000..224e1e57a
--- /dev/null
+++ b/library/src/actions/maxCodePoints/index.ts
@@ -0,0 +1 @@
+export * from './maxCodePoints.ts';
diff --git a/library/src/actions/maxCodePoints/maxCodePoints.test-d.ts b/library/src/actions/maxCodePoints/maxCodePoints.test-d.ts
new file mode 100644
index 000000000..ebf02cc6f
--- /dev/null
+++ b/library/src/actions/maxCodePoints/maxCodePoints.test-d.ts
@@ -0,0 +1,50 @@
+import { describe, expectTypeOf, test } from 'vitest';
+import type { InferInput, InferIssue, InferOutput } from '../../types/index.ts';
+import {
+  maxCodePoints,
+  type MaxCodePointsAction,
+  type MaxCodePointsIssue,
+} from './maxCodePoints.ts';
+
+describe('maxCodePoints', () => {
+  describe('should return action object', () => {
+    test('with undefined message', () => {
+      type Action = MaxCodePointsAction<string, 10, undefined>;
+      expectTypeOf(maxCodePoints<string, 10>(10)).toEqualTypeOf<Action>();
+      expectTypeOf(
+        maxCodePoints<string, 10, undefined>(10, undefined)
+      ).toEqualTypeOf<Action>();
+    });
+
+    test('with string message', () => {
+      expectTypeOf(
+        maxCodePoints<string, 10, 'message'>(10, 'message')
+      ).toEqualTypeOf<MaxCodePointsAction<string, 10, 'message'>>();
+    });
+
+    test('with function message', () => {
+      expectTypeOf(
+        maxCodePoints<string, 10, () => string>(10, () => 'message')
+      ).toEqualTypeOf<MaxCodePointsAction<string, 10, () => string>>();
+    });
+  });
+
+  describe('should infer correct types', () => {
+    type Input = 'example string';
+    type Action = MaxCodePointsAction<Input, 10, undefined>;
+
+    test('of input', () => {
+      expectTypeOf<InferInput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of output', () => {
+      expectTypeOf<InferOutput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of issue', () => {
+      expectTypeOf<InferIssue<Action>>().toEqualTypeOf<
+        MaxCodePointsIssue<Input, 10>
+      >();
+    });
+  });
+});
diff --git a/library/src/actions/maxCodePoints/maxCodePoints.test.ts b/library/src/actions/maxCodePoints/maxCodePoints.test.ts
new file mode 100644
index 000000000..cf5363abb
--- /dev/null
+++ b/library/src/actions/maxCodePoints/maxCodePoints.test.ts
@@ -0,0 +1,150 @@
+import { describe, expect, test } from 'vitest';
+import type { StringIssue } from '../../schemas/index.ts';
+import { _getCodePointCount } from '../../utils/index.ts';
+import { expectActionIssue, expectNoActionIssue } from '../../vitest/index.ts';
+import {
+  maxCodePoints,
+  type MaxCodePointsAction,
+  type MaxCodePointsIssue,
+} from './maxCodePoints.ts';
+
+describe('maxCodePoints', () => {
+  describe('should return action object', () => {
+    const baseAction: Omit<MaxCodePointsAction<string, 5, never>, 'message'> = {
+      kind: 'validation',
+      type: 'max_code_points',
+      reference: maxCodePoints,
+      expects: '<=5',
+      requirement: 5,
+      async: false,
+      '~validate': expect.any(Function),
+    };
+
+    test('with undefined message', () => {
+      const action: MaxCodePointsAction<string, 5, undefined> = {
+        ...baseAction,
+        message: undefined,
+      };
+      expect(maxCodePoints(5)).toStrictEqual(action);
+      expect(maxCodePoints(5, undefined)).toStrictEqual(action);
+    });
+
+    test('with string message', () => {
+      expect(maxCodePoints(5, 'message')).toStrictEqual({
+        ...baseAction,
+        message: 'message',
+      } satisfies MaxCodePointsAction<string, 5, string>);
+    });
+
+    test('with function message', () => {
+      const message = () => 'message';
+      expect(maxCodePoints(5, message)).toStrictEqual({
+        ...baseAction,
+        message,
+      } satisfies MaxCodePointsAction<string, 5, typeof message>);
+    });
+  });
+
+  describe('should return dataset without issues', () => {
+    const action = maxCodePoints(5);
+
+    test('for untyped inputs', () => {
+      const issues: [StringIssue] = [
+        {
+          kind: 'schema',
+          type: 'string',
+          input: null,
+          expected: 'string',
+          received: 'null',
+          message: 'message',
+        },
+      ];
+      expect(
+        action['~validate']({ typed: false, value: null, issues }, {})
+      ).toStrictEqual({
+        typed: false,
+        value: null,
+        issues,
+      });
+    });
+
+    test('for valid strings', () => {
+      expectNoActionIssue(action, ['', ' ', '1', 'foo', '12345', '12 45']);
+    });
+
+    test('for valid emoji', () => {
+      expectNoActionIssue(action, ['😀', '😀👋🏼🧩', '😶‍🌫️👍', '1️⃣', '1️⃣㊙️']);
+    });
+
+    test('for valid non-latin', () => {
+      expectNoActionIssue(action, [
+        '𠮷野家', // billboard notation
+        '𠮷田太郎',
+        '𠮷野家で𩸽',
+        '奈良葛󠄀城',
+        '奈良葛城市',
+        '竈門禰豆子',
+        'あ𛀙よろし',
+        // We rarely see the following notations in the wild today (some antique restaurants or shops)
+        '天𛂱゚𛃭', // 天ぷら (tempura)
+        '𛁟゙ん𛀸゙', // だんご (🍡)
+      ]);
+    });
+  });
+
+  describe('should return dataset with issues', () => {
+    const action = maxCodePoints(5, 'message');
+    const baseIssue: Omit<
+      MaxCodePointsIssue<string, 5>,
+      'input' | 'received'
+    > = {
+      kind: 'validation',
+      type: 'max_code_points',
+      expected: '<=5',
+      message: 'message',
+      requirement: 5,
+    };
+
+    test('for invalid strings', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['123456', '12345 ', '123456789', 'foo bar baz'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid emoji', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        [
+          '1️⃣2️⃣',
+          '😶‍🌫️👍👍',
+          '😀👋🏼🧩👩🏻‍🏫',
+          '😀👋🏼🧩👩🏻‍🏫🫥',
+          '😀👋🏼🧩👩🏻‍🏫🫥🫠',
+          '😀👋🏼🧩👩🏻‍🏫🫥🫠🧑‍💻👻🥎',
+        ],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid non-latin', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        [
+          // The culprit is E+0100
+          '奈良葛󠄀城市',
+          '奈良県葛城市',
+          '奈良県葛󠄀城市',
+          '竈門禰󠄀豆子',
+          // 🍡: 1 code point emoji & U+3099 consumes one more code points
+          '𛁟゙ん𛀸゙🍡',
+        ],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+  });
+});
diff --git a/library/src/actions/maxCodePoints/maxCodePoints.ts b/library/src/actions/maxCodePoints/maxCodePoints.ts
new file mode 100644
index 000000000..c0fd2a4f9
--- /dev/null
+++ b/library/src/actions/maxCodePoints/maxCodePoints.ts
@@ -0,0 +1,134 @@
+import type {
+  BaseIssue,
+  BaseValidation,
+  ErrorMessage,
+} from '../../types/index.ts';
+import { _addIssue, _getCodePointCount } from '../../utils/index.ts';
+
+/**
+ * Max code points issue type.
+ */
+export interface MaxCodePointsIssue<
+  TInput extends string,
+  TRequirement extends number,
+> extends BaseIssue<TInput> {
+  /**
+   * The issue kind.
+   */
+  readonly kind: 'validation';
+  /**
+   * The issue type.
+   */
+  readonly type: 'max_code_points';
+  /**
+   * The expected property.
+   */
+  readonly expected: `<=${TRequirement}`;
+  /**
+   * The received property.
+   */
+  readonly received: `${number}`;
+  /**
+   * The maximum code points.
+   */
+  readonly requirement: TRequirement;
+}
+
+/**
+ * Max code points action type.
+ */
+export interface MaxCodePointsAction<
+  TInput extends string,
+  TRequirement extends number,
+  TMessage extends
+    | ErrorMessage<MaxCodePointsIssue<TInput, TRequirement>>
+    | undefined,
+> extends BaseValidation<
+    TInput,
+    TInput,
+    MaxCodePointsIssue<TInput, TRequirement>
+  > {
+  /**
+   * The action type.
+   */
+  readonly type: 'max_code_points';
+  /**
+   * The action reference.
+   */
+  readonly reference: typeof maxCodePoints;
+  /**
+   * The expected property.
+   */
+  readonly expects: `<=${TRequirement}`;
+  /**
+   * The maximum code points.
+   */
+  readonly requirement: TRequirement;
+  /**
+   * The error message.
+   */
+  readonly message: TMessage;
+}
+
+/**
+ * Creates a max code points validation action.
+ *
+ * @param requirement The maximum code points.
+ *
+ * @returns A max code points action.
+ */
+export function maxCodePoints<
+  TInput extends string,
+  const TRequirement extends number,
+>(
+  requirement: TRequirement
+): MaxCodePointsAction<TInput, TRequirement, undefined>;
+
+/**
+ * Creates a max code points validation action.
+ *
+ * @param requirement The maximum code points.
+ * @param message The error message.
+ *
+ * @returns A max code points action.
+ */
+export function maxCodePoints<
+  TInput extends string,
+  const TRequirement extends number,
+  const TMessage extends
+    | ErrorMessage<MaxCodePointsIssue<TInput, TRequirement>>
+    | undefined,
+>(
+  requirement: TRequirement,
+  message: TMessage
+): MaxCodePointsAction<TInput, TRequirement, TMessage>;
+
+export function maxCodePoints(
+  requirement: number,
+  message?: ErrorMessage<MaxCodePointsIssue<string, number>>
+): MaxCodePointsAction<
+  string,
+  number,
+  ErrorMessage<MaxCodePointsIssue<string, number>> | undefined
+> {
+  return {
+    kind: 'validation',
+    type: 'max_code_points',
+    reference: maxCodePoints,
+    async: false,
+    expects: `<=${requirement}`,
+    requirement,
+    message,
+    '~validate'(dataset, config) {
+      if (dataset.typed) {
+        const count = _getCodePointCount(dataset.value);
+        if (count > this.requirement) {
+          _addIssue(this, 'code_points', dataset, config, {
+            received: `${count}`,
+          });
+        }
+      }
+      return dataset;
+    },
+  };
+}
diff --git a/library/src/actions/minCodePoints/index.ts b/library/src/actions/minCodePoints/index.ts
new file mode 100644
index 000000000..81315d4a3
--- /dev/null
+++ b/library/src/actions/minCodePoints/index.ts
@@ -0,0 +1 @@
+export * from './minCodePoints.ts';
diff --git a/library/src/actions/minCodePoints/minCodePoints.test-d.ts b/library/src/actions/minCodePoints/minCodePoints.test-d.ts
new file mode 100644
index 000000000..502c3fdba
--- /dev/null
+++ b/library/src/actions/minCodePoints/minCodePoints.test-d.ts
@@ -0,0 +1,50 @@
+import { describe, expectTypeOf, test } from 'vitest';
+import type { InferInput, InferIssue, InferOutput } from '../../types/index.ts';
+import {
+  minCodePoints,
+  type MinCodePointsAction,
+  type MinCodePointsIssue,
+} from './minCodePoints.ts';
+
+describe('minCodePoints', () => {
+  describe('should return action object', () => {
+    test('with undefined message', () => {
+      type Action = MinCodePointsAction<string, 10, undefined>;
+      expectTypeOf(minCodePoints<string, 10>(10)).toEqualTypeOf<Action>();
+      expectTypeOf(
+        minCodePoints<string, 10, undefined>(10, undefined)
+      ).toEqualTypeOf<Action>();
+    });
+
+    test('with string message', () => {
+      expectTypeOf(
+        minCodePoints<string, 10, 'message'>(10, 'message')
+      ).toEqualTypeOf<MinCodePointsAction<string, 10, 'message'>>();
+    });
+
+    test('with function message', () => {
+      expectTypeOf(
+        minCodePoints<string, 10, () => string>(10, () => 'message')
+      ).toEqualTypeOf<MinCodePointsAction<string, 10, () => string>>();
+    });
+  });
+
+  describe('should infer correct types', () => {
+    type Input = 'example string';
+    type Action = MinCodePointsAction<Input, 10, undefined>;
+
+    test('of input', () => {
+      expectTypeOf<InferInput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of output', () => {
+      expectTypeOf<InferOutput<Action>>().toEqualTypeOf<Input>();
+    });
+
+    test('of issue', () => {
+      expectTypeOf<InferIssue<Action>>().toEqualTypeOf<
+        MinCodePointsIssue<Input, 10>
+      >();
+    });
+  });
+});
diff --git a/library/src/actions/minCodePoints/minCodePoints.test.ts b/library/src/actions/minCodePoints/minCodePoints.test.ts
new file mode 100644
index 000000000..0ad992c4a
--- /dev/null
+++ b/library/src/actions/minCodePoints/minCodePoints.test.ts
@@ -0,0 +1,157 @@
+import { describe, expect, test } from 'vitest';
+import type { StringIssue } from '../../schemas/index.ts';
+import { _getCodePointCount } from '../../utils/index.ts';
+import { expectActionIssue, expectNoActionIssue } from '../../vitest/index.ts';
+import {
+  minCodePoints,
+  type MinCodePointsAction,
+  type MinCodePointsIssue,
+} from './minCodePoints.ts';
+
+describe('minCodePoints', () => {
+  describe('should return action object', () => {
+    const baseAction: Omit<MinCodePointsAction<string, 5, never>, 'message'> = {
+      kind: 'validation',
+      type: 'min_code_points',
+      reference: minCodePoints,
+      expects: '>=5',
+      requirement: 5,
+      async: false,
+      '~validate': expect.any(Function),
+    };
+
+    test('with undefined message', () => {
+      const action: MinCodePointsAction<string, 5, undefined> = {
+        ...baseAction,
+        message: undefined,
+      };
+      expect(minCodePoints(5)).toStrictEqual(action);
+      expect(minCodePoints(5, undefined)).toStrictEqual(action);
+    });
+
+    test('with string message', () => {
+      expect(minCodePoints(5, 'message')).toStrictEqual({
+        ...baseAction,
+        message: 'message',
+      } satisfies MinCodePointsAction<string, 5, string>);
+    });
+
+    test('with function message', () => {
+      const message = () => 'message';
+      expect(minCodePoints(5, message)).toStrictEqual({
+        ...baseAction,
+        message,
+      } satisfies MinCodePointsAction<string, 5, typeof message>);
+    });
+  });
+
+  describe('should return dataset without issues', () => {
+    const action = minCodePoints(5);
+
+    test('for untyped inputs', () => {
+      const issues: [StringIssue] = [
+        {
+          kind: 'schema',
+          type: 'string',
+          input: null,
+          expected: 'string',
+          received: 'null',
+          message: 'message',
+        },
+      ];
+      expect(
+        action['~validate']({ typed: false, value: null, issues }, {})
+      ).toStrictEqual({
+        typed: false,
+        value: null,
+        issues,
+      });
+    });
+
+    test('for valid strings', () => {
+      expectNoActionIssue(action, [
+        '12345',
+        '1234 ',
+        '123456',
+        '123456789',
+        'foo bar baz',
+      ]);
+    });
+
+    test('for valid emoji', () => {
+      expectNoActionIssue(action, [
+        '1️⃣㊙️',
+        '1️⃣2️⃣',
+        '😶‍🌫️👍',
+        '😶‍🌫️👍👍',
+        '😀👋🏼🧩👩🏻‍🏫',
+        '😀👋🏼🧩👩🏻‍🏫🫥',
+        '😀👋🏼🧩👩🏻‍🏫🫥🫠',
+        '😀👋🏼🧩👩🏻‍🏫🫥🫠🧑‍💻👻🥎',
+      ]);
+    });
+
+    test('for valid non-latin', () => {
+      expectNoActionIssue(action, [
+        '𠮷野家で𩸽',
+        '奈良葛󠄀城', // valid thanks to U+E0100
+        '奈良葛城市',
+        '奈良葛󠄀城市',
+        '奈良県葛城市',
+        '奈良県葛󠄀城市',
+        '竈門禰豆子',
+        '竈門禰󠄀豆子',
+        'あ𛀙よろし',
+        '𛁟゙ん𛀸゙', // だんご
+        '𛁟゙ん𛀸゙🍡',
+      ]);
+    });
+  });
+
+  describe('should return dataset with issues', () => {
+    const action = minCodePoints(5, 'message');
+    const baseIssue: Omit<
+      MinCodePointsIssue<string, 5>,
+      'input' | 'received'
+    > = {
+      kind: 'validation',
+      type: 'min_code_points',
+      expected: '>=5',
+      message: 'message',
+      requirement: 5,
+    };
+
+    test('for invalid strings', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['', ' ', '1', 'foo', '1234', '12 4'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid emoji', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        ['1️⃣', '😀', '😀👋🏼🧩'],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+
+    test('for invalid non-latin', () => {
+      expectActionIssue(
+        action,
+        baseIssue,
+        [
+          '𠮷野家', // billboard notation
+          '葛飾区',
+          '𠮷田太郎',
+          '葛󠄀城市',
+          '天𛂱゚𛃭', // 天ぷら (tempura)
+        ],
+        (value) => `${_getCodePointCount(value)}`
+      );
+    });
+  });
+});
diff --git a/library/src/actions/minCodePoints/minCodePoints.ts b/library/src/actions/minCodePoints/minCodePoints.ts
new file mode 100644
index 000000000..474ed0337
--- /dev/null
+++ b/library/src/actions/minCodePoints/minCodePoints.ts
@@ -0,0 +1,134 @@
+import type {
+  BaseIssue,
+  BaseValidation,
+  ErrorMessage,
+} from '../../types/index.ts';
+import { _addIssue, _getCodePointCount } from '../../utils/index.ts';
+
+/**
+ * Min code points issue type.
+ */
+export interface MinCodePointsIssue<
+  TInput extends string,
+  TRequirement extends number,
+> extends BaseIssue<TInput> {
+  /**
+   * The issue kind.
+   */
+  readonly kind: 'validation';
+  /**
+   * The issue type.
+   */
+  readonly type: 'min_code_points';
+  /**
+   * The expected property.
+   */
+  readonly expected: `>=${TRequirement}`;
+  /**
+   * The received property.
+   */
+  readonly received: `${number}`;
+  /**
+   * The minimum code points.
+   */
+  readonly requirement: TRequirement;
+}
+
+/**
+ * Min code points action type.
+ */
+export interface MinCodePointsAction<
+  TInput extends string,
+  TRequirement extends number,
+  TMessage extends
+    | ErrorMessage<MinCodePointsIssue<TInput, TRequirement>>
+    | undefined,
+> extends BaseValidation<
+    TInput,
+    TInput,
+    MinCodePointsIssue<TInput, TRequirement>
+  > {
+  /**
+   * The action type.
+   */
+  readonly type: 'min_code_points';
+  /**
+   * The action reference.
+   */
+  readonly reference: typeof minCodePoints;
+  /**
+   * The expected property.
+   */
+  readonly expects: `>=${TRequirement}`;
+  /**
+   * The minimum code points.
+   */
+  readonly requirement: TRequirement;
+  /**
+   * The error message.
+   */
+  readonly message: TMessage;
+}
+
+/**
+ * Creates a min code points validation action.
+ *
+ * @param requirement The minimum code points.
+ *
+ * @returns A min code points action.
+ */
+export function minCodePoints<
+  TInput extends string,
+  const TRequirement extends number,
+>(
+  requirement: TRequirement
+): MinCodePointsAction<TInput, TRequirement, undefined>;
+
+/**
+ * Creates a min code points validation action.
+ *
+ * @param requirement The minimum code points.
+ * @param message The error message.
+ *
+ * @returns A min code points action.
+ */
+export function minCodePoints<
+  TInput extends string,
+  const TRequirement extends number,
+  const TMessage extends
+    | ErrorMessage<MinCodePointsIssue<TInput, TRequirement>>
+    | undefined,
+>(
+  requirement: TRequirement,
+  message: TMessage
+): MinCodePointsAction<TInput, TRequirement, TMessage>;
+
+export function minCodePoints(
+  requirement: number,
+  message?: ErrorMessage<MinCodePointsIssue<string, number>>
+): MinCodePointsAction<
+  string,
+  number,
+  ErrorMessage<MinCodePointsIssue<string, number>> | undefined
+> {
+  return {
+    kind: 'validation',
+    type: 'min_code_points',
+    reference: minCodePoints,
+    async: false,
+    expects: `>=${requirement}`,
+    requirement,
+    message,
+    '~validate'(dataset, config) {
+      if (dataset.typed) {
+        const count = _getCodePointCount(dataset.value);
+        if (count < this.requirement) {
+          _addIssue(this, 'code_points', dataset, config, {
+            received: `${count}`,
+          });
+        }
+      }
+      return dataset;
+    },
+  };
+}
diff --git a/library/src/utils/_getCodePointCount/_getCodePointCount.test.ts b/library/src/utils/_getCodePointCount/_getCodePointCount.test.ts
new file mode 100644
index 000000000..937f2ab14
--- /dev/null
+++ b/library/src/utils/_getCodePointCount/_getCodePointCount.test.ts
@@ -0,0 +1,16 @@
+import { describe, expect, test } from 'vitest';
+import { _getCodePointCount } from './_getCodePointCountCount.ts';
+
+describe('_getCodePointCount', () => {
+  test('should return code points count', () => {
+    expect(_getCodePointCount('hello world')).toBe(11);
+    expect(_getCodePointCount('😀')).toBe(1);
+    expect(_getCodePointCount('👨🏽‍👩🏽‍👧🏽‍👦🏽')).toBe(11);
+    expect(_getCodePointCount('𝄞')).toBe(1);
+    expect(_getCodePointCount('😶‍🌫️')).toBe(4);
+    expect(_getCodePointCount('竈門禰󠄀豆子')).toBe(6); // 禰󠄀 = U+79B0 (禰) + U+E0100
+    expect(_getCodePointCount('𛁟゙ん𛀸゙')).toBe(5);
+    expect(_getCodePointCount('奈良県葛󠄀城市')).toBe(7);
+    expect(_getCodePointCount('𠮷野家で𩸽')).toBe(5);
+  });
+});
diff --git a/library/src/utils/_getCodePointCount/_getCodePointCountCount.ts b/library/src/utils/_getCodePointCount/_getCodePointCountCount.ts
new file mode 100644
index 000000000..168010686
--- /dev/null
+++ b/library/src/utils/_getCodePointCount/_getCodePointCountCount.ts
@@ -0,0 +1,23 @@
+/**
+ * Returns the code point count of the input.
+ *
+ * @param input The input to be measured.
+ *
+ * @returns The code point count.
+ *
+ * @internal
+ */
+export function _getCodePointCount(input: string): number {
+  let count: number = 0;
+  for (let i = 0; i < input.length; ) {
+    // If codePoint were undefined here, we would have already got out of loop
+    const codePoint = input.codePointAt(i)!;
+    if (codePoint <= 65535) {
+      i++;
+    } else {
+      i += 2; // 2 characters (surrogate pair) in JS (UTF-16)
+    }
+    count++;
+  }
+  return count;
+}
diff --git a/library/src/utils/_getCodePointCount/index.ts b/library/src/utils/_getCodePointCount/index.ts
new file mode 100644
index 000000000..ed44da436
--- /dev/null
+++ b/library/src/utils/_getCodePointCount/index.ts
@@ -0,0 +1 @@
+export * from './_getCodePointCountCount.ts';
diff --git a/library/src/utils/index.ts b/library/src/utils/index.ts
index 8237d3ddf..95c69d5c4 100644
--- a/library/src/utils/index.ts
+++ b/library/src/utils/index.ts
@@ -1,5 +1,6 @@
 export * from './_addIssue/index.ts';
 export * from './_getByteCount/index.ts';
+export * from './_getCodePointCount/index.ts';
 export * from './_getGraphemeCount/index.ts';
 export * from './_getWordCount/index.ts';
 export * from './_isLuhnAlgo/index.ts';