graphql-schema-diff 0.2.0

Semantic diffing for GraphQL schemas
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211

use crate::{ast, DefinitionKind, DiffMap, DiffState};
use std::{collections::hash_map::Entry, hash::Hash};

/// Traverse the source and target schemas, populating the `DiffState`.
pub(crate) fn traverse_schemas<'a>(
    [source, target]: [Option<&'a ast::TypeSystemDocument>; 2],
    state: &mut DiffState<'a>,
) {
    let [source_definitions_len, target_definitions_len] =
        [source, target].map(|schema| schema.map(|schema| schema.definitions().len()).unwrap_or_default());
    let schema_size_approx = source_definitions_len.max(target_definitions_len);
    state.types_map.reserve(schema_size_approx);
    state.fields_map.reserve(schema_size_approx);

    if let Some(source) = source {
        traverse_source(source, state);
    }

    if let Some(target) = target {
        traverse_target(target, state);
    }
}

fn traverse_source<'a>(source: &'a ast::TypeSystemDocument, state: &mut DiffState<'a>) {
    for tpe in source.definitions() {
        match tpe {
            ast::Definition::Schema(def) | ast::Definition::SchemaExtension(def) => {
                state.schema_definition_map[0] = Some(def);
            }
            ast::Definition::Directive(directive_def) => {
                insert_source(&mut state.types_map, directive_def.name(), DefinitionKind::Directive);
            }
            ast::Definition::Type(tpe) | ast::Definition::TypeExtension(tpe) => {
                let type_name = tpe.name();

                match &tpe {
                    ast::TypeDefinition::Scalar(_) => {
                        state.types_map.insert(type_name, (Some(DefinitionKind::Scalar), None));
                    }
                    ast::TypeDefinition::Object(obj) => {
                        state.types_map.insert(type_name, (Some(DefinitionKind::Object), None));
                        insert_source(
                            &mut state.interface_impls,
                            type_name,
                            obj.implements_interfaces().collect(),
                        );

                        for field in obj.fields() {
                            let field_name = field.name();

                            insert_source(&mut state.fields_map, [type_name, field_name], Some(field.ty()));

                            let mut args = field.arguments();
                            fill_args_src(&mut state.arguments_map, type_name, field_name, &mut args);
                        }
                    }
                    ast::TypeDefinition::Interface(iface) => {
                        state
                            .types_map
                            .insert(type_name, (Some(DefinitionKind::Interface), None));
                        insert_source(
                            &mut state.interface_impls,
                            type_name,
                            iface.implements_interfaces().collect(),
                        );

                        for field in iface.fields() {
                            let field_name = field.name();

                            insert_source(&mut state.fields_map, [type_name, field_name], Some(field.ty()));

                            fill_args_src(&mut state.arguments_map, type_name, field_name, &mut field.arguments());
                        }
                    }
                    ast::TypeDefinition::Union(union) => {
                        state.types_map.insert(type_name, (Some(DefinitionKind::Union), None));

                        for member in union.members() {
                            insert_source(&mut state.fields_map, [type_name, member], None);
                        }
                    }
                    ast::TypeDefinition::Enum(enm) => {
                        state.types_map.insert(type_name, (Some(DefinitionKind::Enum), None));

                        for value in enm.values() {
                            insert_source(&mut state.fields_map, [type_name, value.value()], None);
                        }
                    }
                    ast::TypeDefinition::InputObject(input) => {
                        state
                            .types_map
                            .insert(type_name, (Some(DefinitionKind::InputObject), None));

                        for field in input.fields() {
                            insert_source(&mut state.fields_map, [type_name, field.name()], Some(field.ty()));
                        }
                    }
                }
            }
        }
    }
}

fn traverse_target<'a>(target: &'a ast::TypeSystemDocument, state: &mut DiffState<'a>) {
    for tpe in target.definitions() {
        match tpe {
            ast::Definition::Schema(def) | ast::Definition::SchemaExtension(def) => {
                state.schema_definition_map[1] = Some(def);
            }
            ast::Definition::Directive(directive_def) => {
                merge_target(state.types_map.entry(directive_def.name()), DefinitionKind::Directive);
            }
            ast::Definition::Type(tpe) | ast::Definition::TypeExtension(tpe) => {
                let type_name = tpe.name();

                match tpe {
                    ast::TypeDefinition::Scalar(_) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::Scalar);
                    }
                    ast::TypeDefinition::Object(obj) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::Object);
                        merge_target(
                            state.interface_impls.entry(type_name),
                            obj.implements_interfaces().collect(),
                        );

                        for field in obj.fields() {
                            merge_target(state.fields_map.entry([type_name, field.name()]), Some(field.ty()));
                            let mut args = field.arguments();
                            args_target(&mut state.arguments_map, type_name, field.name(), &mut args);
                        }
                    }
                    ast::TypeDefinition::Interface(iface) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::Interface);
                        merge_target(
                            state.interface_impls.entry(type_name),
                            iface.implements_interfaces().collect(),
                        );

                        for field in iface.fields() {
                            let field_name = field.name();

                            merge_target(state.fields_map.entry([type_name, field_name]), Some(field.ty()));
                            args_target(&mut state.arguments_map, type_name, field_name, &mut field.arguments());
                        }
                    }
                    ast::TypeDefinition::Union(union) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::Union);

                        for member in union.members() {
                            merge_target(state.fields_map.entry([type_name, member]), None);
                        }
                    }
                    ast::TypeDefinition::Enum(enm) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::Enum);

                        for value in enm.values() {
                            merge_target(state.fields_map.entry([type_name, value.value()]), None);
                        }
                    }
                    ast::TypeDefinition::InputObject(input) => {
                        state.types_map.entry(type_name).or_default().1 = Some(DefinitionKind::InputObject);

                        for field in input.fields() {
                            merge_target(state.fields_map.entry([type_name, field.name()]), Some(field.ty()));
                        }
                    }
                }
            }
        }
    }
}

// Insert the arguments of a field into the DiffState.
fn fill_args_src<'a>(
    arguments_map: &mut DiffMap<[&'a str; 3], (ast::Type<'a>, Option<ast::Value<'a>>)>,
    parent: &'a str,
    field: &'a str,
    args: &mut (dyn Iterator<Item = ast::InputValueDefinition<'a>> + 'a),
) {
    for arg in args {
        insert_source(
            arguments_map,
            [parent, field, (arg.name())],
            (arg.ty(), arg.default_value()),
        )
    }
}

// Merge the arguments of a field in the target schema into the DiffState.
fn args_target<'a>(
    arguments_map: &mut DiffMap<[&'a str; 3], (ast::Type<'a>, Option<ast::Value<'a>>)>,
    parent: &'a str,
    field: &'a str,
    args: &mut (dyn Iterator<Item = ast::InputValueDefinition<'a>> + 'a),
) {
    for arg in args {
        merge_target(
            arguments_map.entry([parent, field, arg.name()]),
            (arg.ty(), arg.default_value()),
        )
    }
}

fn insert_source<K: Hash + Eq, V>(map: &mut DiffMap<K, V>, key: K, source: V) {
    map.insert(key, (Some(source), None));
}

fn merge_target<K, V>(entry: Entry<'_, K, (Option<V>, Option<V>)>, target: V) {
    entry.or_default().1 = Some(target);
}