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92 lines
2.4 KiB
Rust
92 lines
2.4 KiB
Rust
use crate::commands::WholeStreamCommand;
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use crate::context::CommandRegistry;
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use crate::prelude::*;
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use nu_errors::ShellError;
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use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
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use nu_source::Tagged;
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use nu_value_ext::ValueExt;
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#[derive(Deserialize)]
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struct DefaultArgs {
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column: Tagged<String>,
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value: Value,
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}
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pub struct Default;
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impl WholeStreamCommand for Default {
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fn name(&self) -> &str {
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"default"
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}
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fn signature(&self) -> Signature {
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Signature::build("default")
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.required("column name", SyntaxShape::String, "the name of the column")
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.required(
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"column value",
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SyntaxShape::Any,
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"the value of the column to default",
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)
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}
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fn usage(&self) -> &str {
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"Sets a default row's column if missing."
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}
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fn run(
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&self,
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args: CommandArgs,
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registry: &CommandRegistry,
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) -> Result<OutputStream, ShellError> {
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default(args, registry)
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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description: "Give a default 'target' to all file entries",
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example: "ls -af | default target 'nothing'",
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result: None,
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}]
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}
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}
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fn default(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
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let registry = registry.clone();
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let stream = async_stream! {
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let (DefaultArgs { column, value }, mut input) = args.process(®istry).await?;
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while let Some(item) = input.next().await {
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let should_add = match item {
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Value {
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value: UntaggedValue::Row(ref r),
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..
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} => r.get_data(&column.item).borrow().is_none(),
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_ => false,
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};
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if should_add {
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match item.insert_data_at_path(&column.item, value.clone()) {
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Some(new_value) => yield ReturnSuccess::value(new_value),
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None => yield ReturnSuccess::value(item),
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}
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} else {
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yield ReturnSuccess::value(item);
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}
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}
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};
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Ok(stream.to_output_stream())
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}
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#[cfg(test)]
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mod tests {
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use super::Default;
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#[test]
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fn examples_work_as_expected() {
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use crate::examples::test as test_examples;
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test_examples(Default {})
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}
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}
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