libgraphql-parser 0.0.5

A blazing fast, error-focused, lossless GraphQL parser for schema, executable, and mixed documents.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

//! Tests for Directive Annotations.
//!
//! These tests verify that directive annotations are correctly parsed and
//! their AST structure is accurate.
//!
//! Written by Claude Code, reviewed by a human.

use crate::GraphQLParseErrorKind;
use crate::tests::ast_utils::extract_first_object_type;
use crate::tests::utils::parse_schema;

/// Verifies that a simple directive `@deprecated` is parsed correctly with
/// the correct directive name and no arguments.
///
/// Per GraphQL spec:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_simple() {
    let obj = extract_first_object_type("type Query { field: String @deprecated }");
    let field = &obj.fields[0];

    assert_eq!(field.directives.len(), 1);
    assert_eq!(field.directives[0].name.value, "deprecated");
    assert!(field.directives[0].arguments.is_empty());
}

/// Verifies that a directive with arguments `@deprecated(reason: "old")` is
/// parsed correctly, including argument name and count.
///
/// Per GraphQL spec:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_with_args() {
    let obj = extract_first_object_type(
        r#"type Query { field: String @deprecated(reason: "old") }"#,
    );
    let field = &obj.fields[0];

    assert_eq!(field.directives.len(), 1);
    assert_eq!(field.directives[0].name.value, "deprecated");
    assert_eq!(field.directives[0].arguments.len(), 1);
    assert_eq!(field.directives[0].arguments[0].name.value, "reason");
}

/// Verifies that multiple directives `@a @b @c` are parsed as three separate
/// directive entries in the correct order.
///
/// Per GraphQL spec:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_multiple() {
    let obj = extract_first_object_type("type Query { field: String @a @b @c }");
    let field = &obj.fields[0];

    assert_eq!(field.directives.len(), 3);
    assert_eq!(field.directives[0].name.value, "a");
    assert_eq!(field.directives[1].name.value, "b");
    assert_eq!(field.directives[2].name.value, "c");
}

/// Verifies that a directive with multiple arguments `@dir(a: 1, b: 2)` is
/// parsed correctly with both arguments present.
///
/// Per GraphQL spec:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_arg_list() {
    let obj = extract_first_object_type("type Query { field: String @dir(a: 1, b: 2) }");
    let field = &obj.fields[0];

    assert_eq!(field.directives.len(), 1);
    assert_eq!(field.directives[0].name.value, "dir");
    assert_eq!(field.directives[0].arguments.len(), 2);
    assert_eq!(field.directives[0].arguments[0].name.value, "a");
    assert_eq!(field.directives[0].arguments[1].name.value, "b");
}

/// Verifies that empty directive arguments `@dir()` produce a parse error.
///
/// Per GraphQL spec, if parentheses are present, at least one argument is
/// required:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_empty_args_error() {
    let result = parse_schema("type Query { field: String @dir() }");
    assert!(result.has_errors());

    // Verify we get exactly one error and it's about an invalid empty construct
    assert_eq!(result.errors().len(), 1);
    assert!(
        matches!(
            result.errors()[0].kind(),
            GraphQLParseErrorKind::InvalidEmptyConstruct { .. },
        ),
        "Expected InvalidEmptyConstruct error, got: {:?}",
        result.errors()[0].kind(),
    );
}

/// Verifies that GraphQL keywords like `type` and `query` can be used as
/// directive names (`@type`, `@query`).
///
/// Per GraphQL spec, directive names can be any name:
/// <https://spec.graphql.org/September2025/#sec-Language.Directives>
///
/// Written by Claude Code, reviewed by a human.
#[test]
fn directive_name_keyword() {
    // Test @type
    let obj_type = extract_first_object_type("type Query { field: String @type }");
    let field_type = &obj_type.fields[0];
    assert_eq!(field_type.directives.len(), 1);
    assert_eq!(field_type.directives[0].name.value, "type");

    // Test @query
    let obj_query = extract_first_object_type("type Query { field: String @query }");
    let field_query = &obj_query.fields[0];
    assert_eq!(field_query.directives.len(), 1);
    assert_eq!(field_query.directives[0].name.value, "query");
}