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nu_command/debug/
metadata_set.rs

1use super::util::{extend_record_with_metadata, parse_metadata_from_record};
2use nu_engine::{ClosureEvalOnce, command_prelude::*};
3use nu_protocol::{DataSource, engine::Closure, shell_error::generic::GenericError};
4
5#[derive(Clone)]
6pub struct MetadataSet;
7
8impl Command for MetadataSet {
9    fn name(&self) -> &str {
10        "metadata set"
11    }
12
13    fn description(&self) -> &str {
14        "Set the metadata for items in the stream."
15    }
16
17    fn signature(&self) -> nu_protocol::Signature {
18        Signature::build("metadata set")
19            .input_output_types(vec![(Type::Any, Type::Any)])
20            .optional(
21                "closure",
22                SyntaxShape::Closure(Some(vec![SyntaxShape::record()])),
23                "A closure that receives the current metadata and returns a new metadata record. Cannot be used with other flags.",
24            )
25            .named(
26                "datasource-filepath",
27                SyntaxShape::Filepath,
28                "Assign the DataSource::FilePath metadata to the input.",
29                Some('f'),
30            )
31            .named(
32                "path-columns",
33                SyntaxShape::List(Box::new(SyntaxShape::String)),
34                "A list of columns in the input for which path metadata will be assigned.",
35                Some('p'),
36            )
37            .named(
38                "content-type",
39                SyntaxShape::OneOf(vec![SyntaxShape::String, SyntaxShape::Nothing]),
40                "Assign content type metadata to the input.",
41                Some('c'),
42            )
43            .named(
44                "table-width-priority-columns",
45                SyntaxShape::List(Box::new(SyntaxShape::String)),
46                "A list of columns to prioritize during table width allocation.",
47                Some('w'),
48            )
49            .allow_variants_without_examples(true)
50            .category(Category::Debug)
51    }
52
53    fn run(
54        &self,
55        engine_state: &EngineState,
56        stack: &mut Stack,
57        call: &Call,
58        mut input: PipelineData,
59    ) -> Result<PipelineData, ShellError> {
60        let head = call.head;
61        let closure: Option<Closure> = call.opt(engine_state, stack, 0)?;
62        let ds_fp: Option<String> = call.get_flag(engine_state, stack, "datasource-filepath")?;
63        let path_columns: Option<Vec<String>> =
64            call.get_flag(engine_state, stack, "path-columns")?;
65        let content_type: Option<Option<String>> =
66            call.get_flag(engine_state, stack, "content-type")?;
67        let table_width_priority_columns: Option<Vec<String>> =
68            call.get_flag(engine_state, stack, "table-width-priority-columns")?;
69
70        let mut metadata = match &mut input {
71            PipelineData::Value(_, metadata)
72            | PipelineData::ListStream(_, metadata)
73            | PipelineData::ByteStream(_, metadata) => metadata.take().unwrap_or_default(),
74            PipelineData::Empty => return Err(ShellError::PipelineEmpty { dst_span: head }),
75        };
76
77        // Handle closure parameter - mutually exclusive with flags
78        if let Some(closure) = closure {
79            if ds_fp.is_some()
80                || path_columns.is_some()
81                || content_type.is_some()
82                || table_width_priority_columns.is_some()
83            {
84                return Err(ShellError::Generic(
85                    GenericError::new(
86                        "Incompatible parameters",
87                        "cannot use closure with other flags",
88                        head,
89                    )
90                    .with_help("Use either the closure parameter or flags, not both"),
91                ));
92            }
93
94            let record = extend_record_with_metadata(Record::new(), Some(&metadata), head);
95            let metadata_value = record.into_value(head);
96
97            let result = ClosureEvalOnce::new(engine_state, stack, closure)
98                .run_with_value(metadata_value)?
99                .into_value(head)?;
100
101            let result_record = result.as_record().map_err(|err| {
102                ShellError::Generic(
103                    GenericError::new(
104                        "Closure must return a record",
105                        format!("got {}", result.get_type()),
106                        head,
107                    )
108                    .with_help("The closure should return a record with metadata fields")
109                    .with_inner([err]),
110                )
111            })?;
112
113            metadata = parse_metadata_from_record(result_record);
114            return Ok(input.set_metadata(Some(metadata)));
115        }
116
117        if let Some(path_columns) = path_columns {
118            metadata.path_columns = path_columns;
119        }
120
121        if let Some(table_width_priority_columns) = table_width_priority_columns {
122            metadata.set_table_width_priority_columns(head, table_width_priority_columns);
123        }
124
125        // Flag-based metadata modification
126        if let Some(content_type) = content_type {
127            metadata.content_type = content_type;
128        }
129
130        if let Some(path) = ds_fp {
131            metadata.data_source = DataSource::FilePath(path.into());
132        }
133
134        Ok(input.set_metadata(Some(metadata)))
135    }
136
137    fn examples(&self) -> Vec<Example<'_>> {
138        vec![
139            Example {
140                description: "Set the metadata of a table literal so the `name` column is treated as a path.",
141                example: "[[name color]; [Cargo.lock '#ff0000'] [Cargo.toml '#00ff00'] [README.md '#0000ff']] | metadata set --path-columns [name]",
142                result: None,
143            },
144            Example {
145                description: "Set the metadata of a file path.",
146                example: "'crates' | metadata set --datasource-filepath $'(pwd)/crates'",
147                result: None,
148            },
149            Example {
150                description: "Set the content type metadata.",
151                example: "'crates' | metadata set --content-type text/plain | metadata | get content_type",
152                result: Some(Value::test_string("text/plain")),
153            },
154            Example {
155                description: "Merge custom metadata.",
156                example: r#""data" | metadata set {|| merge {custom_key: "value"}} | metadata | get custom_key"#,
157                result: None,
158            },
159            Example {
160                description: "Set metadata using a closure.",
161                example: r#""data" | metadata set --content-type "text/csv" | metadata set {|m| $m | update content_type {$in + "-processed"}} | metadata | get content_type"#,
162                result: Some(Value::test_string("text/csv-processed")),
163            },
164            Example {
165                description: "Set table width-priority columns metadata.",
166                example: r#""data" | metadata set --table-width-priority-columns [command virtual] | metadata | get table_width_priority_columns | str join ",""#,
167                result: Some(Value::test_string("command,virtual")),
168            },
169        ]
170    }
171}
172
173#[cfg(test)]
174mod test {
175    use super::*;
176
177    #[test]
178    fn test_examples() -> nu_test_support::Result {
179        nu_test_support::test().examples(MetadataSet)
180    }
181}