Merge pull request #12 from kraken-tech/tweak-type-error-handling

Tweak type error handling

.pre-commit-config.yaml

@@ -26,21 +26,21 @@ repos:
  hooks:
  - id: ruff-lint
  name: "lint Python code with ruff"
- entry: "ruff check"
+ entry: "ruff check --fix"
  language: system
  types: [python]
  require_serial: true
 
  - id: ruff-format
  name: "check Python formatting with ruff"
- entry: "ruff format --check"
+ entry: "ruff format"
  language: system
  types: [python]
  require_serial: true
 
  - id: cargo-format
  name: "check Rust formatting"
- entry: "cargo fmt -- --check"
+ entry: "cargo fmt --"
  language: system
  types: [ rust ]
  require_serial: true

CHANGELOG.md

@@ -7,6 +7,9 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+- Raise TypeError if variable key is not a string.
+- Fall back to displaying variable name if there is a type issue with a variable.
+
 ## [0.1.0a3] - 2024-09-25
 
 - Limited Fluent variable types to strings and integers.

README.md

@@ -98,11 +98,13 @@ bundle = rustfluent.Bundle(
 
 `str`: the translated message.
 
+If there is a problem with a passed variable (e.g. it is of the wrong type or an integer that is larger than a
+signed long integer), then the name of the variable will be used instead.
+
 #### Raises
 
 - `ValueError` if the message could not be found or has no translation available.
-- `TypeError` if a passed variable is not an instance of `str` or `int`, or if the `int` overflows a signed long
- integer (i.e. it's not in the range -2,147,483,648 to 2,147,483,647).
+- `TypeError` if a passed variable name (i.e. a key in the `variables` dict) is not a string.
 
 ## Contributing
 

src/lib.rs

@@ -85,25 +85,38 @@ impl Bundle {
 
  if let Some(variables) = variables {
  for variable in variables {
- let key: String = variable.0.to_string();
+ // Make sure the variable key is a Python string,
+ // raising a TypeError if not.
+ let python_key = variable.0;
+ if !python_key.is_instance_of::<PyString>() {
+ return Err(PyTypeError::new_err(format!(
+ "Variable key not a str, got {}.",
+ python_key
+ )));
+ }
+ let key = python_key.to_string();
+ // Set the variable value as a string or integer,
+ // raising a TypeError if not.
  let python_value = variable.1;
  if python_value.is_instance_of::<PyString>() {
  args.set(key, python_value.to_string());
  } else if python_value.is_instance_of::<PyInt>() {
- let int_value: i32 = match python_value.extract() {
- Ok(value) => value,
+ match python_value.extract::<i32>() {
+ Ok(int_value) => {
+ args.set(key, int_value);
+ }
  _ => {
- return Err(PyTypeError::new_err(format!(
-  "Integer variable was too large: {}.",
-  python_value
- )));
+ // The Python integer overflowed i32.
+ // Fall back to displaying the variable key as its value.
+ let fallback_value = key.clone();
+ args.set(key, fallback_value);
  }
- };
- args.set(key, int_value);
+ }
  } else {
- return Err(PyTypeError::new_err(
- "Expected a string, integer or float.".to_string(),
- ));
+ // The variable value was of an unsupported type.
+ // Fall back to displaying the variable key as its value.
+ let fallback_value = key.clone();
+ args.set(key, fallback_value);
  }
  }
  }

tests/test_python_interface.py

@@ -50,24 +50,35 @@ def test_variables_of_different_types(description, identifier, variables, expect
  assert result == expected
 
 
-def test_large_python_integers_fail_sensibly():
+@pytest.mark.parametrize(
+ "key",
+ (
+ object(),
+ 34.3,
+ 10,
+ ),
+)
+def test_invalid_variable_keys_raise_type_error(key):
  bundle = fluent.Bundle("en", [str(data_dir / "en.ftl")])
 
- with pytest.raises(
- TypeError, match=re.escape("Integer variable was too large: 1000000000000.")
- ):
- bundle.get_translation(
- "hello-user",
- variables={"user": 1_000_000_000_000},
- )
+ with pytest.raises(TypeError, match="Variable key not a str, got"):
+ bundle.get_translation("hello-user", variables={key: "Bob"})
 
 
-@pytest.mark.parametrize("user", (object(), 34.3))
-def test_invalid_type_raises_type_error(user):
+@pytest.mark.parametrize(
+ "value",
+ (
+ object(),
+ 34.3,
+ 1_000_000_000_000, # Larger than signed long integer.
+ ),
+)
+def test_invalid_variable_values_use_key_instead(value):
  bundle = fluent.Bundle("en", [str(data_dir / "en.ftl")])
 
- with pytest.raises(TypeError):
- bundle.get_translation("hello-user", variables={"user": user})
+ result = bundle.get_translation("hello-user", variables={"user": value})
+
+ assert result == f"Hello, {BIDI_OPEN}user{BIDI_CLOSE}"
 
 
 def test_fr_basic():