caco3_web/
figment.rs

1use figment::providers::Serialized;
2use figment::Figment;
3use serde_json::Value;
4use thiserror::Error;
5
6mod private {
7    pub trait Sealed {}
8
9    impl Sealed for figment::Figment {}
10}
11
12#[derive(Debug, Error)]
13#[non_exhaustive]
14pub enum RemoveExistingKeyError<'a> {
15    #[error("key {0} not found")]
16    NotFound(&'a str),
17}
18
19/// Extension trait for `figment::Figment`.
20pub trait FigmentExt: Sized + private::Sealed {
21    /// Remove existing keys.
22    ///
23    /// This method error if key doesn't exist.
24    fn remove_existing_keys<'a, T: AsRef<str>>(
25        &self,
26        keys: &'a [T],
27    ) -> Result<Self, RemoveExistingKeyError<'a>>;
28
29    /// Check for key existent.
30    ///
31    /// blank key return `false`.
32    fn has_key(&self, key: &str) -> bool;
33}
34
35impl FigmentExt for Figment {
36    fn remove_existing_keys<'a, T: AsRef<str>>(
37        &self,
38        keys: &'a [T],
39    ) -> Result<Self, RemoveExistingKeyError<'a>> {
40        let mut value = self.extract::<Value>().expect("json serializable value");
41        let mut pointer = String::new();
42        let mut parts = vec![];
43        for key in keys {
44            let key = key.as_ref();
45            if !self.has_key(key) {
46                return Err(RemoveExistingKeyError::NotFound(key));
47            }
48            pointer.clear();
49            parts.clear();
50            parts.extend(key.split('.'));
51            // note: .expect("object") should never fail because we already check key existent
52            match parts.as_slice() {
53                [] => {
54                    // we already check key existent
55                    unreachable!("empty parts");
56                }
57                [field] => {
58                    value.as_object_mut().expect("object").remove(*field);
59                }
60                [components @ .., field] => {
61                    for c in components {
62                        pointer.push('/');
63                        pointer.push_str(c);
64                    }
65                    value
66                        .pointer_mut(&pointer)
67                        .and_then(Value::as_object_mut)
68                        .expect("object")
69                        .remove(*field);
70                }
71            }
72        }
73        Ok(Figment::from(Serialized::defaults(value)))
74    }
75
76    fn has_key(&self, key: &str) -> bool {
77        self.find_metadata(key).is_some() && !key.is_empty()
78    }
79}
80
81#[cfg(test)]
82mod tests {
83    use super::*;
84
85    fn get_test_figment() -> Figment {
86        Figment::from(Serialized::defaults(serde_json::json!({
87            "foo": {
88                "bar": {
89                    "baz": {
90                        "name": "Baz",
91                    }
92                },
93                "s": "Foo string",
94            },
95            "vec": ["foo", "bar", "baz"],
96        })))
97    }
98
99    #[test]
100    fn remove_existing_keys() {
101        let figment = get_test_figment();
102
103        #[rustfmt::skip]
104        let keys = [
105            "foo.bar.baz.name",
106            "foo.s",
107        ];
108        for key in keys {
109            assert!(figment.has_key(key));
110        }
111        let actual = figment.remove_existing_keys(&keys);
112        let f = actual.expect("keys removed");
113        for key in keys {
114            assert!(!f.has_key(key));
115        }
116    }
117
118    #[test]
119    fn remove_missing_key() {
120        let figment = get_test_figment();
121        let key = "foo.not_exist";
122        assert!(!figment.has_key(key));
123        let keys = [key];
124        let actual = figment.remove_existing_keys(&keys);
125        let err = actual.expect_err("key doesn't exist");
126        assert!(matches!(err, RemoveExistingKeyError::NotFound(_)));
127    }
128
129    #[test]
130    fn has_key() {
131        let figment = get_test_figment();
132        assert!(!figment.has_key(""));
133    }
134}
caco3_web/figment.rs

caco3_web/
figment.rs
