es_fluent_cli/ftl/
parse.rs

1//! FTL file parsing utilities.
2//!
3//! Provides shared functions for parsing FTL files and extracting
4//! message information.
5
6use anyhow::Result;
7use fluent_syntax::{ast, parser};
8use std::collections::HashSet;
9use std::fs;
10use std::path::Path;
11
12/// Parse an FTL file and return the resource.
13///
14/// Returns an empty resource if the file doesn't exist or is empty.
15/// Uses partial parse recovery for files with syntax errors.
16pub fn parse_ftl_file(ftl_path: &Path) -> Result<ast::Resource<String>> {
17    if !ftl_path.exists() {
18        return Ok(ast::Resource { body: Vec::new() });
19    }
20
21    let content = fs::read_to_string(ftl_path)?;
22
23    if content.trim().is_empty() {
24        return Ok(ast::Resource { body: Vec::new() });
25    }
26
27    match parser::parse(content) {
28        Ok(res) => Ok(res),
29        Err((res, _)) => Ok(res), // Use partial result on parse errors
30    }
31}
32
33/// Extract message keys from a resource.
34pub fn extract_message_keys(resource: &ast::Resource<String>) -> HashSet<String> {
35    resource
36        .body
37        .iter()
38        .filter_map(|entry| {
39            if let ast::Entry::Message(msg) = entry {
40                Some(msg.id.name.clone())
41            } else {
42                None
43            }
44        })
45        .collect()
46}
47
48/// Extract variables from a message.
49pub fn extract_variables_from_message(msg: &ast::Message<String>) -> HashSet<String> {
50    let mut variables = HashSet::new();
51    if let Some(ref value) = msg.value {
52        extract_variables_from_pattern(value, &mut variables);
53    }
54    for attr in &msg.attributes {
55        extract_variables_from_pattern(&attr.value, &mut variables);
56    }
57    variables
58}
59
60/// Extract variables from a pattern.
61pub fn extract_variables_from_pattern(
62    pattern: &ast::Pattern<String>,
63    variables: &mut HashSet<String>,
64) {
65    for element in &pattern.elements {
66        if let ast::PatternElement::Placeable { expression } = element {
67            extract_variables_from_expression(expression, variables);
68        }
69    }
70}
71
72/// Extract variables from an expression.
73fn extract_variables_from_expression(
74    expression: &ast::Expression<String>,
75    variables: &mut HashSet<String>,
76) {
77    match expression {
78        ast::Expression::Inline(inline) => {
79            extract_variables_from_inline(inline, variables);
80        },
81        ast::Expression::Select { selector, variants } => {
82            extract_variables_from_inline(selector, variables);
83            for variant in variants {
84                extract_variables_from_pattern(&variant.value, variables);
85            }
86        },
87    }
88}
89
90/// Extract variables from an inline expression.
91fn extract_variables_from_inline(
92    inline: &ast::InlineExpression<String>,
93    variables: &mut HashSet<String>,
94) {
95    match inline {
96        ast::InlineExpression::VariableReference { id } => {
97            variables.insert(id.name.clone());
98        },
99        ast::InlineExpression::FunctionReference { arguments, .. } => {
100            for arg in &arguments.positional {
101                extract_variables_from_inline(arg, variables);
102            }
103            for arg in &arguments.named {
104                extract_variables_from_inline(&arg.value, variables);
105            }
106        },
107        ast::InlineExpression::Placeable { expression } => {
108            extract_variables_from_expression(expression, variables);
109        },
110        _ => {},
111    }
112}
113
114#[cfg(test)]
115mod tests {
116    use super::*;
117
118    #[test]
119    fn test_parse_ftl_file_nonexistent() {
120        let result = parse_ftl_file(Path::new("/nonexistent/path.ftl")).unwrap();
121        assert!(result.body.is_empty());
122    }
123
124    #[test]
125    fn test_extract_message_keys() {
126        let content = "hello = Hello\nworld = World";
127        let resource = parser::parse(content.to_string()).unwrap();
128        let keys = extract_message_keys(&resource);
129
130        assert!(keys.contains("hello"));
131        assert!(keys.contains("world"));
132        assert_eq!(keys.len(), 2);
133    }
134
135    #[test]
136    fn test_extract_variables() {
137        let content = "hello = Hello { $name }, you have { $count } messages";
138        let resource = parser::parse(content.to_string()).unwrap();
139
140        if let ast::Entry::Message(msg) = &resource.body[0] {
141            let vars = extract_variables_from_message(msg);
142            assert!(vars.contains("name"));
143            assert!(vars.contains("count"));
144            assert_eq!(vars.len(), 2);
145        } else {
146            panic!("Expected a message");
147        }
148    }
149
150    #[test]
151    fn test_extract_variables_from_select() {
152        let content = r#"count = { $num ->
153    [one] One item
154   *[other] { $num } items
155}"#;
156        let resource = parser::parse(content.to_string()).unwrap();
157
158        if let ast::Entry::Message(msg) = &resource.body[0] {
159            let vars = extract_variables_from_message(msg);
160            assert!(vars.contains("num"));
161        } else {
162            panic!("Expected a message");
163        }
164    }
165}
es_fluent_cli/ftl/parse.rs

es_fluent_cli/ftl/
parse.rs
