libyang 2.2.0

YANG parser in Rust
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
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230

// Integration tests for YANG 1.1 feature / if-feature support.
//
// tests/yang/iffeature-base.yang defines features `iso`, `extra` and
// `dep` (which depends on `iso`), imports `remote` from
// iffeature-features, and guards a leaf, a container, a uses, a choice
// case and an augment with them. A feature is off unless
// `YangStore::enable_feature` marks it supported, so the guarded nodes
// are pruned from the entry tree by default and appear once the right
// features are enabled.

use libyang::{Diagnostic, Entry, YangStore, YangType, to_entry};
use std::rc::Rc;

fn load(name: &str, features: &[(&str, &str)]) -> (Rc<Entry>, Vec<Diagnostic>) {
    let mut store = YangStore::new();
    store.add_path("tests/yang");
    for (module, feature) in features {
        store.enable_feature(module, feature);
    }
    store.read_with_resolve(name).expect("parse / resolve");
    store.identity_resolve();
    let module = store.find_module(name).expect("module found");
    let entry = to_entry(&store, module);
    let diagnostics = store.take_diagnostics();
    (entry, diagnostics)
}

fn find_child(ent: &Rc<Entry>, name: &str) -> Option<Rc<Entry>> {
    ent.dir.borrow().iter().find(|e| e.name == name).cloned()
}

fn has_child(ent: &Rc<Entry>, name: &str) -> bool {
    find_child(ent, name).is_some()
}

#[test]
fn all_features_off_prunes_guarded_nodes() {
    let (root, diagnostics) = load("iffeature-base", &[]);
    let routing = find_child(&root, "routing").expect("routing container");

    // Unguarded nodes stay: the plain leaf and the ungated choice
    // case's flattened child.
    assert!(has_child(&routing, "name"));
    assert!(has_child(&routing, "tcp-port"));

    // Every guarded node is pruned.
    for gated in [
        "dhcp",
        "iso-only",
        "both",
        "gated-dep",
        "remote-gated",
        "shared-leaf",
        "tsel",
    ] {
        assert!(
            !has_child(&routing, gated),
            "feature-gated node \"{gated}\" should be pruned by default"
        );
    }

    // The gated augment targets the gated (absent) container; being
    // disabled itself, it must vanish silently rather than report a
    // target-not-found diagnostic.
    assert!(
        diagnostics.is_empty(),
        "no diagnostics expected, got {diagnostics:?}"
    );
}

#[test]
fn enable_feature_exposes_guarded_nodes() {
    let (root, diagnostics) = load("iffeature-base", &[("iffeature-base", "iso")]);
    let routing = find_child(&root, "routing").expect("routing container");

    assert!(has_child(&routing, "dhcp"));
    assert!(has_child(&routing, "shared-leaf"), "uses gated by iso");

    // The gated container is back, complete with the gated augment's
    // contribution.
    let iso_only = find_child(&routing, "iso-only").expect("iso-only container");
    assert!(has_child(&iso_only, "nsap"));
    assert!(has_child(&iso_only, "net"), "augment gated by iso applies");

    // The osi choice case is back and carries its choice/case tags.
    let tsel = find_child(&routing, "tsel").expect("tsel leaf from osi case");
    assert_eq!(tsel.choice.borrow().as_deref(), Some("transport"));
    assert_eq!(tsel.case.borrow().as_deref(), Some("osi"));

    // Still gated by features that remain off.
    assert!(!has_child(&routing, "both"), "extra is still off");
    assert!(!has_child(&routing, "gated-dep"), "dep is still off");
    assert!(!has_child(&routing, "remote-gated"));

    assert!(
        diagnostics.is_empty(),
        "no diagnostics expected, got {diagnostics:?}"
    );
}

#[test]
fn compound_expression_needs_both_features() {
    let (root, _) = load(
        "iffeature-base",
        &[("iffeature-base", "iso"), ("iffeature-base", "extra")],
    );
    let routing = find_child(&root, "routing").expect("routing container");
    assert!(has_child(&routing, "both"), "if-feature \"iso and extra\"");
}

#[test]
fn dependent_feature_requires_its_own_if_feature() {
    // `dep` declares `if-feature iso`, so enabling it alone is not
    // enough (RFC 7950 section 7.20.1).
    let (root, _) = load("iffeature-base", &[("iffeature-base", "dep")]);
    let routing = find_child(&root, "routing").expect("routing container");
    assert!(
        !has_child(&routing, "gated-dep"),
        "dep without iso must stay disabled"
    );

    let (root, _) = load(
        "iffeature-base",
        &[("iffeature-base", "dep"), ("iffeature-base", "iso")],
    );
    let routing = find_child(&root, "routing").expect("routing container");
    assert!(has_child(&routing, "gated-dep"));
}

#[test]
fn prefixed_reference_resolves_to_imported_module() {
    // `remote-gated` is guarded by `ifx:remote`, defined in the
    // imported iffeature-features module — enabling it there turns the
    // leaf on; enabling a same-named feature in the wrong module does
    // not.
    let (root, _) = load("iffeature-base", &[("iffeature-features", "remote")]);
    let routing = find_child(&root, "routing").expect("routing container");
    assert!(has_child(&routing, "remote-gated"));

    let (root, _) = load("iffeature-base", &[("iffeature-base", "remote")]);
    let routing = find_child(&root, "routing").expect("routing container");
    assert!(!has_child(&routing, "remote-gated"));
}

#[test]
fn unknown_feature_reference_is_diagnosed_and_disabled() {
    let (root, diagnostics) = load("iffeature-unknown", &[]);
    let top_box = find_child(&root, "top-box").expect("top-box container");

    assert!(has_child(&top_box, "fine"));
    assert!(!has_child(&top_box, "oops"), "dangling reference disables");
    assert!(
        diagnostics.contains(&Diagnostic::UnknownFeature {
            module: "iffeature-unknown".to_string(),
            feature: "no-such".to_string(),
        }),
        "expected UnknownFeature diagnostic, got {diagnostics:?}"
    );
}

#[test]
fn feature_gated_enum_arms_are_filtered() {
    let enum_names = |e: &Rc<Entry>| -> Vec<String> {
        e.type_node
            .as_ref()
            .expect("type resolved")
            .enum_stmt
            .iter()
            .map(|en| en.name.clone())
            .collect()
    };
    let union_enum_arm = |e: &Rc<Entry>| -> Vec<String> {
        e.type_node
            .as_ref()
            .expect("type resolved")
            .union
            .iter()
            .find(|arm| arm.kind == YangType::Enumeration)
            .expect("enumeration arm in union")
            .enum_stmt
            .iter()
            .map(|en| en.name.clone())
            .collect()
    };

    // Default: the gated values vanish from the type — in a plain
    // enumeration and inside a union arm — while the leaf itself
    // stays (only the arm is gated, not the node).
    let (root, diagnostics) = load("iffeature-base", &[]);
    let routing = find_child(&root, "routing").expect("routing container");
    let mode = find_child(&routing, "transport-mode").expect("transport-mode leaf");
    assert_eq!(enum_names(&mode), ["tcp"]);
    let addr = find_child(&routing, "addr").expect("addr leaf-list");
    assert_eq!(union_enum_arm(&addr), ["none"]);
    assert!(
        diagnostics.is_empty(),
        "no diagnostics expected, got {diagnostics:?}"
    );

    // With iso enabled both gated values exist.
    let (root, _) = load("iffeature-base", &[("iffeature-base", "iso")]);
    let routing = find_child(&root, "routing").expect("routing container");
    let mode = find_child(&routing, "transport-mode").expect("transport-mode leaf");
    assert_eq!(enum_names(&mode), ["tcp", "osi-tp"]);
    let addr = find_child(&routing, "addr").expect("addr leaf-list");
    assert_eq!(union_enum_arm(&addr), ["dhcp", "none"]);
}

#[test]
fn feature_statements_are_captured_in_the_ast() {
    let mut store = YangStore::new();
    store.add_path("tests/yang");
    store
        .read_with_resolve("iffeature-base")
        .expect("parse / resolve");
    let module = store.find_module("iffeature-base").expect("module found");

    let names: Vec<&str> = module.feature.iter().map(|f| f.name.as_str()).collect();
    assert_eq!(names, ["iso", "extra", "dep"]);

    let iso = &module.feature[0];
    assert_eq!(
        iso.description.as_deref(),
        Some("ISO / OSI protocol support")
    );
    assert!(iso.if_feature.is_empty());

    let dep = &module.feature[2];
    assert_eq!(dep.if_feature.len(), 1, "dep depends on iso");
}