# Description
As title, we can't provide examples for plugin commands, this pr would
make it possible
# User-Facing Changes
Take plugin `nu-example-1` as example:
```
❯ nu-example-1 -h
PluginSignature test 1 for plugin. Returns Value::Nothing
Usage:
> nu-example-1 {flags} <a> <b> (opt) ...(rest)
Flags:
-h, --help - Display the help message for this command
-f, --flag - a flag for the signature
-n, --named <String> - named string
Parameters:
a <int>: required integer value
b <string>: required string value
(optional) opt <int>: Optional number
...rest <string>: rest value string
Examples:
running example with an int value and string value
> nu-example-1 3 bb
```
The examples session is newly added.
## Basic idea behind these changes
when nushell query plugin signatures, plugin just returns it's signature
without any examples, so nushell have no idea about the examples of
plugin commands.
To adding the feature, we just making plugin returns it's signature with
examples.
Before:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<Signature>
```
After:
```
1. get signature
---------------->
Nushell ------------------ Plugin
<-----------------
2. returns Vec<PluginSignature>
```
When writing plugin signature to $nu.plugin-path:
Serialize `<PluginSignature>` rather than `<Signature>`, which would
enable us to serialize examples to `$nu.plugin-path`
## Shortcoming
It's a breaking changes because `Plugin::signature` is changed, and it
requires plugin authors to change their code for new signatures.
Fortunally it should be easy to change, for rust based plugin, we just
need to make a global replace from word `Signature` to word
`PluginSignature` in their plugin project.
Our content of plugin-path is really large, if one plugin have many
examples, it'd results to larger body of $nu.plugin-path, which is not
really scale. A solution would be save register information in other
binary formats rather than `json`. But I think it'd be another story.
# Tests + Formatting
Don't forget to add tests that cover your changes.
Make sure you've run and fixed any issues with these commands:
- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass
# After Submitting
If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
* Skeleton implementation
Lots and lots of TODOs
* Bootstrap simple CustomValue plugin support test
* Create nu_plugin_custom_value
* Skeleton for nu_plugin_custom_values
* Return a custom value from plugin
* Encode CustomValues from plugin calls as PluginResponse::PluginData
* Add new PluginCall variant CollapseCustomValue
* Handle CollapseCustomValue plugin calls
* Add CallInput::Data variant to CallInfo inputs
* Handle CallInfo with CallInput::Data plugin calls
* Send CallInput::Data if Value is PluginCustomValue from plugin calls
* Remove unnecessary boxing of plugins CallInfo
* Add fields needed to collapse PluginCustomValue to it
* Document PluginCustomValue and its purpose
* Impl collapsing using plugin calls in PluginCustomValue::to_base_value
* Implement proper typetag based deserialization for CoolCustomValue
* Test demonstrating that passing back a custom value to plugin works
* Added a failing test for describing plugin CustomValues
* Support describe for PluginCustomValues
- Add name to PluginResponse::PluginData
- Also turn it into a struct for clarity
- Add name to PluginCustomValue
- Return name field from PluginCustomValue
* Demonstrate that plugins can create and handle multiple CustomValues
* Add bincode to nu-plugin dependencies
This is for demonstration purposes, any schemaless binary seralization
format will work. I picked bincode since it's the most popular for Rust
but there are defintely better options out there for this usecase
* serde_json::Value -> Vec<u8>
* Update capnp schema for new CallInfo.input field
* Move call_input capnp serialization and deserialization into new file
* Deserialize Value's span from Value itself instead of passing call.head
I am not sure if this was correct and I am breaking it or if it was a
bug, I don't fully understand how nu creates and uses Spans. What should
reuse spans and what should recreate new ones?
But yeah it felt weird that the Value's Span was being ignored since in
the json serializer just uses the Value's Span
* Add call_info value round trip test
* Add capnp CallInput::Data serialization and deserialization support
* Add CallInfo::CollapseCustomValue to capnp schema
* Add capnp PluginCall::CollapseCustomValue serialization and deserialization support
* Add PluginResponse::PluginData to capnp schema
* Add capnp PluginResponse::PluginData serialization and deserialization support
* Switch plugins::custom_values tests to capnp
Both json and capnp would work now! Sadly I can't choose both at the
same time :(
* Add missing JsonSerializer round trip tests
* Handle plugin returning PluginData as a response to CollapseCustomValue
* Refactor plugin calling into a reusable function
Many less levels of indentation now!
* Export PluginData from nu_plugin
So plugins can create their very own serve_plugin with whatever
CustomValue behavior they may desire
* Error if CustomValue cannot be handled by Plugin
