From 5a0a26896594d09b4620ded37bdc7e60a9d927c1 Mon Sep 17 00:00:00 2001
From: 07pepa <“no@sharebcs.spam”>
Date: Sat, 24 Feb 2024 11:43:24 +0100
Subject: [PATCH] Add language code ISO 639-3 and ISO 639-5 and definitions and
 tests

* added dynamically generated literals based on pycountry
* tested all possibilities and errors exhaustively
---
 pydantic_extra_types/language_code.py | 75 +++++++++++++++++++++++++++
 tests/test_language_codes.py          | 53 +++++++++++++++++++
 2 files changed, 128 insertions(+)
 create mode 100644 pydantic_extra_types/language_code.py
 create mode 100644 tests/test_language_codes.py

diff --git a/pydantic_extra_types/language_code.py b/pydantic_extra_types/language_code.py
new file mode 100644
index 00000000..74b1e0ce
--- /dev/null
+++ b/pydantic_extra_types/language_code.py
@@ -0,0 +1,75 @@
+from typing import Any
+
+from pydantic import GetCoreSchemaHandler, GetJsonSchemaHandler
+from pydantic_core import PydanticCustomError, core_schema
+
+try:
+    import pycountry
+except ModuleNotFoundError:  # pragma: no cover
+    raise RuntimeError(
+        'The `language_code` module requires "pycountry" to be installed.'
+        ' You can install it with "pip install pycountry".'
+    )
+
+
+class ISO639_3(str):
+    # noinspection PyUnresolvedReferences
+    allowed_values_list = [lang.alpha_3 for lang in pycountry.languages]
+    allowed_values = set(allowed_values_list)
+
+    @classmethod
+    def _validate(cls, __input_value: str, _: core_schema.ValidationInfo) -> 'ISO639_3':
+        if __input_value not in cls.allowed_values:
+            raise PydanticCustomError(
+                'ISO649_3', 'Invalid ISO 639-3 language code. See https://en.wikipedia.org/wiki/ISO_639-3'
+            )
+        return cls(__input_value)
+
+    @classmethod
+    def __get_pydantic_core_schema__(
+        cls, _: type[Any], __: GetCoreSchemaHandler
+    ) -> core_schema.AfterValidatorFunctionSchema:
+        return core_schema.with_info_after_validator_function(
+            cls._validate,
+            core_schema.str_schema(min_length=3, max_length=3),
+        )
+
+    @classmethod
+    def __get_pydantic_json_schema__(
+        cls, schema: core_schema.CoreSchema, handler: GetJsonSchemaHandler
+    ) -> dict[str, Any]:
+        json_schema = handler(schema)
+        json_schema.update({'enum': cls.allowed_values_list})
+        return json_schema
+
+
+class ISO639_5(str):
+    # noinspection PyUnresolvedReferences
+    allowed_values_list = [lang.alpha_3 for lang in pycountry.language_families]
+    allowed_values_list.sort()
+    allowed_values = set(allowed_values_list)
+
+    @classmethod
+    def _validate(cls, __input_value: str, _: core_schema.ValidationInfo) -> 'ISO639_5':
+        if __input_value not in cls.allowed_values:
+            raise PydanticCustomError(
+                'ISO649_5', 'Invalid ISO 639-5 language code. See https://en.wikipedia.org/wiki/ISO_639-5'
+            )
+        return cls(__input_value)
+
+    @classmethod
+    def __get_pydantic_core_schema__(
+        cls, _: type[Any], __: GetCoreSchemaHandler
+    ) -> core_schema.AfterValidatorFunctionSchema:
+        return core_schema.with_info_after_validator_function(
+            cls._validate,
+            core_schema.str_schema(min_length=3, max_length=3),
+        )
+
+    @classmethod
+    def __get_pydantic_json_schema__(
+        cls, schema: core_schema.CoreSchema, handler: GetJsonSchemaHandler
+    ) -> dict[str, Any]:
+        json_schema = handler(schema)
+        json_schema.update({'enum': cls.allowed_values_list})
+        return json_schema
diff --git a/tests/test_language_codes.py b/tests/test_language_codes.py
new file mode 100644
index 00000000..f95ebf75
--- /dev/null
+++ b/tests/test_language_codes.py
@@ -0,0 +1,53 @@
+import re
+
+import pycountry
+import pytest
+from pydantic import BaseModel, ValidationError
+
+from pydantic_extra_types import language_code
+
+
+class ISO3CheckingModel(BaseModel):
+    lang: language_code.ISO639_3
+
+
+class ISO5CheckingModel(BaseModel):
+    lang: language_code.ISO639_5
+
+
+@pytest.mark.parametrize('lang', map(lambda lang: lang.alpha_3, pycountry.languages))
+def test_iso_ISO639_3_code_ok(lang: str):
+    model = ISO3CheckingModel(lang=lang)
+    assert model.lang == lang
+
+
+@pytest.mark.parametrize('lang', map(lambda lang: lang.alpha_3, pycountry.language_families))
+def test_iso_639_5_code_ok(lang: str):
+    model = ISO5CheckingModel(lang=lang)
+    assert model.lang == lang
+
+
+def test_iso3_language_fail():
+    with pytest.raises(
+        ValidationError,
+        match=re.escape(
+            '1 validation error for ISO3CheckingModel\nlang\n  '
+            'Value error, LOL is not a valid ISO 639-3 language code. '
+            'See https://en.wikipedia.org/wiki/ISO_639-3. '
+        )
+        + '.+',
+    ):
+        ISO3CheckingModel(lang='LOL')
+
+
+def test_iso5_language_fail():
+    with pytest.raises(
+        ValidationError,
+        match=re.escape(
+            '1 validation error for ISO5CheckingModel\nlang\n  '
+            'Value error, LOL is not a valid ISO 639-5 language code. '
+            'See https://en.wikipedia.org/wiki/ISO_639-5. '
+        )
+        + '.+',
+    ):
+        ISO5CheckingModel(lang='LOL')