Fix shell setting precedence (#1306)

.github/workflows/ci.yaml

@@ -44,7 +44,7 @@ jobs:
       with:
         components: clippy, rustfmt
         override: true
-        toolchain: 1.53.0
+        toolchain: 1.54.0
 
     - uses: Swatinem/rust-cache@v1
 

README.md

@@ -648,7 +648,8 @@ foo:
 | `export`                  | boolean            | Export all variables as environment variables.                                                |
 | `positional-arguments`    | boolean            | Pass positional arguments.                                                                    |
 | `shell`                   | `[COMMAND, ARGS…]` | Set the command used to invoke recipes and evaluate backticks.                                |
-| `windows-powershell`      | boolean            | Use PowerShell on Windows as default shell.                                                   |
+| `windows-shell`           | `[COMMAND, ARGS…]` | Set the command used to invoke recipes and evaluate backticks.                                |
+| `windows-powershell`      | boolean            | Use PowerShell on Windows as default shell. (Deprecated. Use `windows-shell` instead.         |
 
 Boolean settings can be written as:
 
@@ -775,6 +776,8 @@ hello:
   Write-Host "Hello, world!"
 ```
 
+See [powershell.just](https://github.com/casey/just/blob/master/examples/powershell.just) for a justfile that uses PowerShell on all platforms.
+
 ##### Windows PowerShell
 
 *`set windows-powershell` uses the legacy `powershell.exe` binary, and is no longer recommended. See the `windows-shell` setting above for a more flexible way to control which shell is used on Windows.*
@@ -2126,6 +2129,17 @@ foo $argument:
 
 This defeats `just`'s ability to catch typos, for example if you type `$argumant`, but works for all possible values of `argument`, including those with double quotes.
 
+### Configuring the Shell
+
+There are a number of ways to configure the shell for linewise recipes, which are the default when a recipe does not start with a `#!` shebang. Their precedence, from highest to lowest, is:
+
+1. The `--shell` and `--shell-arg` command line options. Passing either of these will cause `just` to ignore any settings in the current justfile.
+2. `set windows-shell := [...]`
+3. `set windows-powershell` (deprecated)
+4. `set shell := [...]`
+
+Since `set windows-shell` has higher precedence than `set shell`, you can use `set windows-shell` to pick a shell on Windows, and `set shell` to pick a shell for all other platforms.
+
 Changelog
 ---------
 

examples/powershell.just

@@ -0,0 +1,29 @@
+# Cross platform shebang:
+shebang := if os() == 'windows' {
+  'powershell.exe'
+} else {
+  '/usr/bin/env pwsh'
+}
+
+# Set shell for non-Windows OSs:
+set shell := ["powershell", "-c"]
+
+# Set shell for Windows OSs:
+set windows-shell := ["powershell.exe", "-NoLogo", "-Command"]
+
+# If you have PowerShell Core installed and want to use it,
+# use `pwsh.exe` instead of `powershell.exe`
+
+linewise:
+  Write-Host "Hello, world!"
+
+shebang:
+	#!{{shebang}}
+	$PSV = $PSVersionTable.PSVersion | % {"$_" -split "\." }
+	$psver = $PSV[0] + "." + $PSV[1]
+	if ($PSV[2].Length -lt 4) {
+		$psver += "." + $PSV[2] + " Core"
+	} else {
+		$psver += " Desktop"
+	}
+	echo "PowerShell $psver"

src/settings.rs

@@ -30,50 +30,48 @@ impl<'src> Settings<'src> {
   }
 
   pub(crate) fn shell_command(&self, config: &Config) -> Command {
-    let mut cmd = Command::new(self.shell_binary(config));
+    let (command, args) = self.shell(config);
 
-    cmd.args(self.shell_arguments(config));
+    let mut cmd = Command::new(command);
+
+    cmd.args(args);
 
     cmd
   }
 
-  pub(crate) fn shell_binary<'a>(&'a self, config: &'a Config) -> &'a str {
-    let shell_or_args_present = config.shell.is_some() || config.shell_args.is_some();
-
-    if let (Some(shell), false) = (&self.shell, shell_or_args_present) {
-      shell.command.cooked.as_ref()
-    } else if let Some(shell) = &config.shell {
-      shell
-    } else if let (true, Some(shell)) = (cfg!(windows), &self.windows_shell) {
-      shell.command.cooked.as_ref()
-    } else if cfg!(windows) && self.windows_powershell {
-      WINDOWS_POWERSHELL_SHELL
-    } else {
-      DEFAULT_SHELL
-    }
-  }
-
-  pub(crate) fn shell_arguments<'a>(&'a self, config: &'a Config) -> Vec<&'a str> {
-    let shell_or_args_present = config.shell.is_some() || config.shell_args.is_some();
-
-    if let (Some(shell), false) = (&self.shell, shell_or_args_present) {
+  pub(crate) fn shell<'a>(&'a self, config: &'a Config) -> (&'a str, Vec<&'a str>) {
+    match (&config.shell, &config.shell_args) {
+      (Some(shell), Some(shell_args)) => (shell, shell_args.iter().map(String::as_ref).collect()),
+      (Some(shell), None) => (shell, DEFAULT_SHELL_ARGS.to_vec()),
+      (None, Some(shell_args)) => (
+        DEFAULT_SHELL,
+        shell_args.iter().map(String::as_ref).collect(),
+      ),
+      (None, None) => {
+        if let (true, Some(shell)) = (cfg!(windows), &self.windows_shell) {
+          (
+            shell.command.cooked.as_ref(),
             shell
               .arguments
               .iter()
               .map(|argument| argument.cooked.as_ref())
-        .collect()
-    } else if let Some(shell_args) = &config.shell_args {
-      shell_args.iter().map(String::as_ref).collect()
-    } else if let (true, Some(shell)) = (cfg!(windows), &self.windows_shell) {
+              .collect(),
+          )
+        } else if cfg!(windows) && self.windows_powershell {
+          (WINDOWS_POWERSHELL_SHELL, WINDOWS_POWERSHELL_ARGS.to_vec())
+        } else if let Some(shell) = &self.shell {
+          (
+            shell.command.cooked.as_ref(),
             shell
               .arguments
               .iter()
               .map(|argument| argument.cooked.as_ref())
-        .collect()
-    } else if cfg!(windows) && self.windows_powershell {
-      WINDOWS_POWERSHELL_ARGS.to_vec()
+              .collect(),
+          )
         } else {
-      DEFAULT_SHELL_ARGS.to_vec()
+          (DEFAULT_SHELL, DEFAULT_SHELL_ARGS.to_vec())
+        }
+      }
     }
   }
 }
@@ -91,8 +89,7 @@ mod tests {
       ..testing::config(&[])
     };
 
-    assert_eq!(settings.shell_binary(&config), "sh");
-    assert_eq!(settings.shell_arguments(&config), vec!["-cu"]);
+    assert_eq!(settings.shell(&config), ("sh", vec!["-cu"]));
   }
 
   #[test]
@@ -106,14 +103,12 @@ mod tests {
     };
 
     if cfg!(windows) {
-      assert_eq!(settings.shell_binary(&config), "powershell.exe");
       assert_eq!(
-        settings.shell_arguments(&config),
-        vec!["-NoLogo", "-Command"]
+        settings.shell(&config),
+        ("powershell.exe", vec!["-NoLogo", "-Command"])
       );
     } else {
-      assert_eq!(settings.shell_binary(&config), "sh");
-      assert_eq!(settings.shell_arguments(&config), vec!["-cu"]);
+      assert_eq!(settings.shell(&config), ("sh", vec!["-cu"]));
     }
   }
 
@@ -128,8 +123,7 @@ mod tests {
       ..testing::config(&[])
     };
 
-    assert_eq!(settings.shell_binary(&config), "lol");
-    assert_eq!(settings.shell_arguments(&config), vec!["-nice"]);
+    assert_eq!(settings.shell(&config), ("lol", vec!["-nice"]));
   }
 
   #[test]
@@ -144,8 +138,7 @@ mod tests {
       ..testing::config(&[])
     };
 
-    assert_eq!(settings.shell_binary(&config), "lol");
-    assert_eq!(settings.shell_arguments(&config), vec!["-nice"]);
+    assert_eq!(settings.shell(&config), ("lol", vec!["-nice"]));
   }
 
   #[test]
@@ -170,8 +163,7 @@ mod tests {
       ..testing::config(&[])
     };
 
-    assert_eq!(settings.shell_binary(&config), "asdf.exe");
-    assert_eq!(settings.shell_arguments(&config), vec!["-nope"]);
+    assert_eq!(settings.shell(&config), ("asdf.exe", vec!["-nope"]));
   }
 
   #[test]
@@ -184,7 +176,7 @@ mod tests {
       ..testing::config(&[])
     };
 
-    assert_eq!(settings.shell_binary(&config), "lol");
+    assert_eq!(settings.shell(&config).0, "lol");
   }
 
   #[test]
@@ -198,12 +190,6 @@ mod tests {
       ..testing::config(&[])
     };
 
-    if cfg!(windows) {
-      assert_eq!(settings.shell_binary(&config), "powershell.exe");
-    } else {
-      assert_eq!(settings.shell_binary(&config), "sh");
-    }
-
-    assert_eq!(settings.shell_arguments(&config), vec!["-nice"]);
+    assert_eq!(settings.shell(&config), ("sh", vec!["-nice"]));
   }
 }

src/subcommand.rs

@@ -217,9 +217,10 @@ impl Subcommand {
     let mut child = match result {
       Ok(child) => child,
       Err(io_error) => {
+        let (shell_binary, shell_arguments) = justfile.settings.shell(config);
         return Err(Error::ChooserInvoke {
-          shell_binary: justfile.settings.shell_binary(config).to_owned(),
-          shell_arguments: justfile.settings.shell_arguments(config).join(" "),
+          shell_binary: shell_binary.to_owned(),
+          shell_arguments: shell_arguments.join(" "),
           chooser,
           io_error,
         });

tests/lib.rs

@@ -76,7 +76,5 @@ mod subsequents;
 mod tempdir;
 mod undefined_variables;
 #[cfg(target_family = "windows")]
-mod windows_powershell;
-#[cfg(target_family = "windows")]
 mod windows_shell;
 mod working_directory;

tests/windows_powershell.rs

@@ -1,18 +0,0 @@
-use super::*;
-
-#[test]
-fn windows_poweshell_setting_uses_powershell() {
-  Test::new()
-    .justfile(
-      r#"
-      set windows-powershell
-
-      foo:
-        Write-Output bar
-    "#,
-    )
-    .shell(false)
-    .stdout("bar\r\n")
-    .stderr("Write-Output bar\n")
-    .run();
-}

tests/windows_shell.rs

@@ -6,6 +6,42 @@ fn windows_shell_setting() {
     .justfile(
       r#"
       set windows-shell := ["pwsh.exe", "-NoLogo", "-Command"]
+      set shell := ["asdfasdfasdfasdf"]
+
+      foo:
+        Write-Output bar
+    "#,
+    )
+    .shell(false)
+    .stdout("bar\r\n")
+    .stderr("Write-Output bar\n")
+    .run();
+}
+
+#[test]
+fn windows_powershell_setting_uses_powershell() {
+  Test::new()
+    .justfile(
+      r#"
+      set windows-powershell
+      set shell := ["asdfasdfasdfasdf"]
+
+      foo:
+        Write-Output bar
+    "#,
+    )
+    .shell(false)
+    .stdout("bar\r\n")
+    .stderr("Write-Output bar\n")
+    .run();
+}
+
+#[test]
+fn windows_poweshell_setting_uses_powershell() {
+  Test::new()
+    .justfile(
+      r#"
+      set windows-powershell
 
       foo:
         Write-Output bar