darklua_core/rules/
empty_do.rs

1use crate::nodes::{Block, Statement};
2use crate::process::{DefaultVisitor, NodeProcessor, NodeVisitor};
3use crate::rules::{
4    Context, FlawlessRule, RuleConfiguration, RuleConfigurationError, RuleProperties,
5};
6
7use super::verify_no_rule_properties;
8
9#[derive(Debug, Default)]
10struct EmptyDoFilter {
11    mutated: bool,
12}
13
14impl EmptyDoFilter {
15    pub fn has_mutated(&self) -> bool {
16        self.mutated
17    }
18}
19
20impl NodeProcessor for EmptyDoFilter {
21    fn process_block(&mut self, block: &mut Block) {
22        block.filter_statements(|statement| match statement {
23            Statement::Do(do_statement) => {
24                self.mutated = do_statement.get_block().is_empty();
25                !self.mutated
26            }
27            _ => true,
28        });
29    }
30}
31
32pub const REMOVE_EMPTY_DO_RULE_NAME: &str = "remove_empty_do";
33
34/// A rule that removes empty do statements.
35#[derive(Debug, Default, PartialEq, Eq)]
36pub struct RemoveEmptyDo {}
37
38impl FlawlessRule for RemoveEmptyDo {
39    fn flawless_process(&self, block: &mut Block, _: &Context) {
40        loop {
41            let mut processor = EmptyDoFilter::default();
42            DefaultVisitor::visit_block(block, &mut processor);
43            if !processor.has_mutated() {
44                break;
45            }
46        }
47    }
48}
49
50impl RuleConfiguration for RemoveEmptyDo {
51    fn configure(&mut self, properties: RuleProperties) -> Result<(), RuleConfigurationError> {
52        verify_no_rule_properties(&properties)?;
53
54        Ok(())
55    }
56
57    fn get_name(&self) -> &'static str {
58        REMOVE_EMPTY_DO_RULE_NAME
59    }
60
61    fn serialize_to_properties(&self) -> RuleProperties {
62        RuleProperties::new()
63    }
64}
65
66#[cfg(test)]
67mod test {
68    use super::*;
69    use crate::nodes::DoStatement;
70    use crate::rules::{ContextBuilder, Rule};
71    use crate::Resources;
72
73    use insta::assert_json_snapshot;
74
75    fn new_rule() -> RemoveEmptyDo {
76        RemoveEmptyDo::default()
77    }
78
79    #[test]
80    fn remove_empty_do_statement() {
81        let rule = new_rule();
82
83        let mut block = Block::default().with_statement(DoStatement::new(Block::default()));
84
85        rule.process(
86            &mut block,
87            &ContextBuilder::new(".", &Resources::from_memory(), "").build(),
88        )
89        .expect("rule should succeed");
90
91        assert_eq!(block, Block::default());
92    }
93
94    #[test]
95    fn remove_nested_empty_do_statement() {
96        let rule = new_rule();
97
98        let block_with_do_statement = Block::default().with_statement(DoStatement::default());
99        let mut block = Block::default().with_statement(DoStatement::new(block_with_do_statement));
100
101        rule.process(
102            &mut block,
103            &ContextBuilder::new(".", &Resources::from_memory(), "").build(),
104        )
105        .expect("rule should succeed");
106
107        assert_eq!(block, Block::default());
108    }
109
110    #[test]
111    fn serialize_default_rule() {
112        let rule: Box<dyn Rule> = Box::new(new_rule());
113
114        assert_json_snapshot!("default_remove_empty_do", rule);
115    }
116
117    #[test]
118    fn configure_with_extra_field_error() {
119        let result = json5::from_str::<Box<dyn Rule>>(
120            r#"{
121            rule: 'remove_empty_do',
122            prop: "something",
123        }"#,
124        );
125        pretty_assertions::assert_eq!(result.unwrap_err().to_string(), "unexpected field 'prop'");
126    }
127}
darklua_core/rules/empty_do.rs

darklua_core/rules/
empty_do.rs
