fn test_extract_simple_aliases()

in cli/src/generate/prepare_grammar/extract_simple_aliases.rs [118:222]

• 97 lines of code
• 1 McCabe index (conditional complexity)

    fn test_extract_simple_aliases() {
        let mut syntax_grammar = SyntaxGrammar {
            variables: vec![
                SyntaxVariable {
                    name: "v1".to_owned(),
                    kind: VariableType::Named,
                    productions: vec![Production {
                        dynamic_precedence: 0,
                        steps: vec![
                            ProductionStep::new(Symbol::terminal(0)).with_alias("a1", true),
                            ProductionStep::new(Symbol::terminal(1)).with_alias("a2", true),
                            ProductionStep::new(Symbol::terminal(2)).with_alias("a3", true),
                        ],
                    }],
                },
                SyntaxVariable {
                    name: "v2".to_owned(),
                    kind: VariableType::Named,
                    productions: vec![Production {
                        dynamic_precedence: 0,
                        steps: vec![
                            // Token 0 is always aliased as "a1".
                            ProductionStep::new(Symbol::terminal(0)).with_alias("a1", true),
                            // Token 1 is aliased above, but not here.
                            ProductionStep::new(Symbol::terminal(1)),
                            // Token 2 is aliased differently than above.
                            ProductionStep::new(Symbol::terminal(2)).with_alias("a4", true),
                        ],
                    }],
                },
            ],
            extra_tokens: Vec::new(),
            expected_conflicts: Vec::new(),
            variables_to_inline: Vec::new(),
            supertype_symbols: Vec::new(),
            external_tokens: Vec::new(),
            word_token: None,
        };

        let lexical_grammar = LexicalGrammar {
            nfa: Nfa::new(),
            variables: vec![
                LexicalVariable {
                    name: "t1".to_string(),
                    kind: VariableType::Anonymous,
                    implicit_precedence: 0,
                    start_state: 0,
                },
                LexicalVariable {
                    name: "t2".to_string(),
                    kind: VariableType::Anonymous,
                    implicit_precedence: 0,
                    start_state: 0,
                },
                LexicalVariable {
                    name: "t3".to_string(),
                    kind: VariableType::Anonymous,
                    implicit_precedence: 0,
                    start_state: 0,
                },
            ],
        };

        let simple_aliases = extract_simple_aliases(&mut syntax_grammar, &lexical_grammar);
        assert_eq!(simple_aliases.len(), 1);
        assert_eq!(
            simple_aliases[&Symbol::terminal(0)],
            Alias {
                value: "a1".to_string(),
                is_named: true,
            }
        );

        assert_eq!(
            syntax_grammar.variables,
            vec![
                SyntaxVariable {
                    name: "v1".to_owned(),
                    kind: VariableType::Named,
                    productions: vec![Production {
                        dynamic_precedence: 0,
                        steps: vec![
                            // 'Simple' alias removed
                            ProductionStep::new(Symbol::terminal(0)),
                            // Other aliases unchanged
                            ProductionStep::new(Symbol::terminal(1)).with_alias("a2", true),
                            ProductionStep::new(Symbol::terminal(2)).with_alias("a3", true),
                        ],
                    },],
                },
                SyntaxVariable {
                    name: "v2".to_owned(),
                    kind: VariableType::Named,
                    productions: vec![Production {
                        dynamic_precedence: 0,
                        steps: vec![
                            ProductionStep::new(Symbol::terminal(0)),
                            ProductionStep::new(Symbol::terminal(1)),
                            ProductionStep::new(Symbol::terminal(2)).with_alias("a4", true),
                        ],
                    },],
                },
            ]
        );
    }