Init shell completions through es init

CHANGELOG.md

@@ -4,9 +4,8 @@
 
 ### Added
 
-- Add shell completions, accessed by enabling the `COMPLETE` environment variable [#6](https://github.com/LucasPickering/env-select/issues/6)
-  - For example, adding `COMPLETE=fish es | source` to your `fish.config` will enable completions for fish
-  - [See docs](https://env-select.lucaspickering.me/book/user_guide/shell_completions.html) for more info and a list of supported shells
+- Add shell completions [#6](https://github.com/LucasPickering/env-select/issues/6)
+  - These will be automatically loaded as part of the existing shell integrations, so if you already have `es init | source` or similar in your shell init file, you don't need to change anything
 - Add command aliases
   - `es r` alias for `es run`, `es s` for `es set`
 

docs/src/SUMMARY.md

@@ -15,7 +15,6 @@
 - [Inheritance & Cascading Configs](./user_guide/inheritance.md)
 - [Side Effects](./user_guide/side_effects.md)
 - [`es run` and Shell Interactions](./user_guide/run_advanced.md)
-- [Shell Completions](./user_guide/shell_completions.md)
 
 # API Reference
 

docs/src/install.md

@@ -6,7 +6,7 @@ See [the artifacts page](/artifacts) to download and install `es` using your pre
 
 While not strictly required, it's highly recommended to install the `es` shell function. This wraps the `es` binary command, allowing it to automatically modify your current shell environment with the `es set` subcommand. Otherwise, you'll have to manually pipe the output of `es set` to `source`.
 
-> If you only plan to use the `es run` command, this is **not relevant**.
+> If you only plan to use the `es run` command, and don't care about shell tab completions, this is **not relevant**.
 
 This is necessary because a child process is not allowed to modify its parent's environment. That means the `es` process cannot modify the environment of the invoking shell. The wrapping shell function takes the output of `es` and runs it in that shell session to update the environment.
 

src/commands/init.rs

@@ -1,6 +1,11 @@
-use crate::commands::{CommandContext, SubcommandTrait};
+use crate::{
+    commands::{CommandContext, SubcommandTrait},
+    Args, COMMAND_NAME,
+};
 use anyhow::Context;
-use clap::Parser;
+use clap::{CommandFactory, Parser};
+use clap_complete::CompleteEnv;
+use std::env;
 
 /// Configure the shell environment for env-select. Intended to be piped
 /// to `source` as part of your shell startup.
@@ -14,6 +19,14 @@ impl SubcommandTrait for InitCommand {
             .init_script()
             .context("Error generating shell init script")?;
         print!("{script}");
+
+        // Print the command to enable shell completions as well. CompleteEnv
+        // doesn't expose the inner machinery that would allow us to print the
+        // line directly, so we have to enable the env var that triggers it
+        env::set_var("COMPLETE", context.shell.kind.to_string());
+        CompleteEnv::with_factory(Args::command)
+            .try_complete([COMMAND_NAME], None)?;
+
         Ok(())
     }
 }

src/main.rs

@@ -17,10 +17,12 @@ use log::{error, LevelFilter};
 use clap_complete::CompleteEnv;
 use std::{path::PathBuf, process::ExitCode};
 
+const COMMAND_NAME: &str = "es";
+
 /// A utility to select between predefined values or sets of environment
 /// variables.
 #[derive(Debug, Parser)]
-#[clap(bin_name = "es", author, version, about, long_about = None)]
+#[clap(bin_name = COMMAND_NAME, author, version, about, long_about = None)]
 pub struct Args {
     #[command(subcommand)]
     command: Commands,

tests/common/mod.rs

@@ -2,6 +2,9 @@ use assert_cmd::Command;
 use rstest_reuse::{self, *};
 use std::path::{Path, PathBuf};
 
+// const ZSH_PRELUDE: &str = "autoload -U +X compinit && compinit";
+const ZSH_PRELUDE: &str = "compinit";
+
 /// Command to run env-select
 pub fn env_select() -> Command {
     let mut command = Command::cargo_bin("es").unwrap();
@@ -47,7 +50,15 @@ pub fn execute_script(
     // Inject the function source into the script
     let function_source = String::from_utf8(assert.get_output().stdout.clone())
         .expect("Function output is not valid UTF-8");
-    let script = format!("{function_source} {script}");
+
+    // Zsh requires an extra command to enable completion. Typically the user
+    // would have this set in their .zshrc
+    let mut script_components = Vec::new();
+    if shell_kind == "zsh" {
+        script_components.push(ZSH_PRELUDE);
+    }
+    script_components.extend([&function_source, script]);
+    let script = script_components.join("\n");
 
     let shell = shell_path(shell_kind);
     let mut command = Command::new(&shell);