vrl/stdlib/
remove.rs

1use crate::compiler::prelude::*;
2use crate::path::{OwnedSegment, OwnedValuePath};
3
4fn remove(path: Value, compact: Value, mut value: Value) -> Resolved {
5    let path = match path {
6        Value::Array(path) => {
7            let mut lookup = OwnedValuePath::root();
8
9            for segment in path {
10                let segment = match segment {
11                    Value::Bytes(field) => {
12                        OwnedSegment::Field(String::from_utf8_lossy(&field).into())
13                    }
14                    #[allow(clippy::cast_possible_truncation)] //TODO evaluate removal options
15                    Value::Integer(index) => OwnedSegment::Index(index as isize),
16                    value => {
17                        return Err(format!(
18                            "path segment must be either string or integer, not {}",
19                            value.kind()
20                        )
21                        .into());
22                    }
23                };
24
25                lookup.segments.push(segment);
26            }
27
28            lookup
29        }
30        value => {
31            return Err(ValueError::Expected {
32                got: value.kind(),
33                expected: Kind::array(Collection::any()),
34            }
35            .into());
36        }
37    };
38    let compact = compact.try_boolean()?;
39    value.remove(&path, compact);
40    Ok(value)
41}
42
43#[derive(Clone, Copy, Debug)]
44pub struct Remove;
45
46impl Function for Remove {
47    fn identifier(&self) -> &'static str {
48        "remove"
49    }
50
51    fn parameters(&self) -> &'static [Parameter] {
52        &[
53            Parameter {
54                keyword: "value",
55                kind: kind::OBJECT | kind::ARRAY,
56                required: true,
57            },
58            Parameter {
59                keyword: "path",
60                kind: kind::ARRAY,
61                required: true,
62            },
63            Parameter {
64                keyword: "compact",
65                kind: kind::BOOLEAN,
66                required: false,
67            },
68        ]
69    }
70
71    fn examples(&self) -> &'static [Example] {
72        &[
73            Example {
74                title: "remove existing field",
75                source: r#"remove!(value: {"foo": "bar"}, path: ["foo"])"#,
76                result: Ok("{}"),
77            },
78            Example {
79                title: "remove unknown field",
80                source: r#"remove!(value: {"foo": "bar"}, path: ["baz"])"#,
81                result: Ok(r#"{ "foo": "bar" }"#),
82            },
83            Example {
84                title: "nested path",
85                source: r#"remove!(value: {"foo": { "bar": true }}, path: ["foo", "bar"])"#,
86                result: Ok(r#"{ "foo": {} }"#),
87            },
88            Example {
89                title: "compact object",
90                source: r#"remove!(value: {"foo": { "bar": true }}, path: ["foo", "bar"], compact: true)"#,
91                result: Ok("{}"),
92            },
93            Example {
94                title: "indexing",
95                source: "remove!(value: [92, 42], path: [0])",
96                result: Ok("[42]"),
97            },
98            Example {
99                title: "nested indexing",
100                source: r#"remove!(value: {"foo": { "bar": [92, 42] }}, path: ["foo", "bar", 1])"#,
101                result: Ok(r#"{ "foo": { "bar": [92] } }"#),
102            },
103            Example {
104                title: "compact array",
105                source: r#"remove!(value: {"foo": [42], "bar": true }, path: ["foo", 0], compact: true)"#,
106                result: Ok(r#"{ "bar": true }"#),
107            },
108            Example {
109                title: "external target",
110                source: indoc! {r#"
111                    . = { "foo": true }
112                    remove!(value: ., path: ["foo"])
113                "#},
114                result: Ok("{}"),
115            },
116            Example {
117                title: "variable",
118                source: indoc! {r#"
119                    var = { "foo": true }
120                    remove!(value: var, path: ["foo"])
121                "#},
122                result: Ok("{}"),
123            },
124            Example {
125                title: "missing index",
126                source: r#"remove!(value: {"foo": { "bar": [92, 42] }}, path: ["foo", "bar", 1, -1])"#,
127                result: Ok(r#"{ "foo": { "bar": [92, 42] } }"#),
128            },
129            Example {
130                title: "invalid indexing",
131                source: r#"remove!(value: [42], path: ["foo"])"#,
132                result: Ok("[42]"),
133            },
134            Example {
135                title: "invalid segment type",
136                source: r#"remove!(value: {"foo": { "bar": [92, 42] }}, path: ["foo", true])"#,
137                result: Err(
138                    r#"function call error for "remove" at (0:65): path segment must be either string or integer, not boolean"#,
139                ),
140            },
141        ]
142    }
143
144    fn compile(
145        &self,
146        _state: &state::TypeState,
147        _ctx: &mut FunctionCompileContext,
148        arguments: ArgumentList,
149    ) -> Compiled {
150        let value = arguments.required("value");
151        let path = arguments.required("path");
152        let compact = arguments.optional("compact").unwrap_or(expr!(false));
153
154        Ok(RemoveFn {
155            value,
156            path,
157            compact,
158        }
159        .as_expr())
160    }
161}
162
163#[derive(Debug, Clone)]
164pub(crate) struct RemoveFn {
165    value: Box<dyn Expression>,
166    path: Box<dyn Expression>,
167    compact: Box<dyn Expression>,
168}
169
170impl FunctionExpression for RemoveFn {
171    fn resolve(&self, ctx: &mut Context) -> Resolved {
172        let path = self.path.resolve(ctx)?;
173        let compact = self.compact.resolve(ctx)?;
174        let value = self.value.resolve(ctx)?;
175
176        remove(path, compact, value)
177    }
178
179    fn type_def(&self, state: &state::TypeState) -> TypeDef {
180        let value_td = self.value.type_def(state);
181
182        let mut td = TypeDef::from(Kind::never()).fallible();
183
184        if value_td.is_array() {
185            td = td.or_array(Collection::any());
186        }
187
188        if value_td.is_object() {
189            td = td.or_object(Collection::any());
190        }
191
192        td
193    }
194}
195
196#[cfg(test)]
197mod tests {
198    use super::*;
199    use crate::value;
200
201    test_function![
202        remove => Remove;
203
204        array {
205            args: func_args![value: value!([42]), path: value!([0])],
206            want: Ok(value!([])),
207            tdef: TypeDef::array(Collection::any()).fallible(),
208        }
209
210        object {
211            args: func_args![value: value!({ "foo": 42 }), path: value!(["foo"])],
212            want: Ok(value!({})),
213            tdef: TypeDef::object(Collection::any()).fallible(),
214        }
215    ];
216}
vrl/stdlib/remove.rs

vrl/stdlib/
remove.rs
