Implement invocation_directory function (#312)

README.adoc

@@ -289,6 +289,24 @@ This is an x86_64 machine
 
 - `env_var_or_default(key, default)` – Retrieves the environment variable with name `key`, returning `default` if it is not present.
 
+==== Invocation Directory
+
+- `invocation_directory()` - Retrieves the path of the current working directory, before `just` changed it (chdir'd) prior to executing commands.
+
+For example, to call `rustfmt` on files just under the "current directory" (from the user/invoker's perspective), use the following rule:
+
+```
+rustfmt:
+    find {{invocation_directory()}} -name \*.rs -exec rustfmt {} \;
+```
+
+Alternatively, if your command needs to be run from the current directory, you could use (e.g.):
+
+```
+build:
+    cd {{invocation_directory()}}; ./some_script_that_needs_to_be_run_from_here
+```
+
 ==== Dotenv Integration
 
 `just` will load environment variables from a file named `.env`. This file can be located in the same directory as your justfile or in a parent directory. These variables are environment variables, not `just` variables, and so must be accessed using `$VARIABLE_NAME` in recipes and backticks.

justfile

@@ -141,6 +141,10 @@ ruby:
 	#!/usr/bin/env ruby
 	puts "Hello from ruby!"
 
+# Print working directory, for demonstration purposes!
+pwd:
+	echo {{invocation_directory()}}
+
 # Local Variables:
 # mode: makefile
 # End:

src/assignment_evaluator.rs

@@ -1,9 +1,12 @@
+use std::path::PathBuf;
+
 use common::*;
 
 use brev;
 
 pub struct AssignmentEvaluator<'a: 'b, 'b> {
   pub assignments: &'b Map<&'a str, Expression<'a>>,
+  pub invocation_directory: &'b Result<PathBuf, String>,
   pub dotenv:      &'b Map<String, String>,
   pub dry_run:     bool,
   pub evaluated:   Map<&'a str, String>,
@@ -17,6 +20,7 @@ pub struct AssignmentEvaluator<'a: 'b, 'b> {
 impl<'a, 'b> AssignmentEvaluator<'a, 'b> {
   pub fn evaluate_assignments(
     assignments: &Map<&'a str, Expression<'a>>,
+    invocation_directory: &Result<PathBuf, String>,
     dotenv:      &'b Map<String, String>,
     overrides:   &Map<&str, &str>,
     quiet:       bool,
@@ -28,6 +32,7 @@ impl<'a, 'b> AssignmentEvaluator<'a, 'b> {
       exports:   &empty(),
       scope:     &empty(),
       assignments,
+      invocation_directory,
       dotenv,
       dry_run,
       overrides,
@@ -107,6 +112,7 @@ impl<'a, 'b> AssignmentEvaluator<'a, 'b> {
           self.evaluate_expression(argument, arguments)
         }).collect::<Result<Vec<String>, RuntimeError>>()?;
         let context = FunctionContext {
+          invocation_directory: &self.invocation_directory,
           dotenv: self.dotenv,
         };
         evaluate_function(token, name, &context, &call_arguments)
@@ -161,10 +167,14 @@ mod test {
   use testing::parse_success;
   use Configuration;
 
+  fn no_cwd_err() -> Result<PathBuf, String> {
+    Err(String::from("no cwd in tests"))
+  }
+
   #[test]
   fn backtick_code() {
     match parse_success("a:\n echo {{`f() { return 100; }; f`}}")
-          .run(&["a"], &Default::default()).unwrap_err() {
+          .run(no_cwd_err(), &["a"], &Default::default()).unwrap_err() {
       RuntimeError::Backtick{token, output_error: OutputError::Code(code)} => {
         assert_eq!(code, 100);
         assert_eq!(token.lexeme, "`f() { return 100; }; f`");
@@ -187,7 +197,7 @@ recipe:
       ..Default::default()
     };
 
-    match parse_success(text).run(&["recipe"], &configuration).unwrap_err() {
+    match parse_success(text).run(no_cwd_err(), &["recipe"], &configuration).unwrap_err() {
       RuntimeError::Backtick{token, output_error: OutputError::Code(_)} => {
         assert_eq!(token.lexeme, "`echo $exported_variable`");
       },

src/function.rs

@@ -1,13 +1,18 @@
+use std::path::PathBuf;
+
 use common::*;
 use target;
 
+use platform::{Platform, PlatformInterface};
+
 lazy_static! {
   static ref FUNCTIONS: Map<&'static str, Function> = vec![
     ("arch",               Function::Nullary(arch              )),
     ("os",                 Function::Nullary(os                )),
     ("os_family",          Function::Nullary(os_family         )),
     ("env_var",            Function::Unary  (env_var           )),
     ("env_var_or_default", Function::Binary (env_var_or_default)),
+    ("invocation_directory", Function::Nullary(invocation_directory)),
   ].into_iter().collect();
 }
 
@@ -29,6 +34,7 @@ impl Function {
 }
 
 pub struct FunctionContext<'a> {
+  pub invocation_directory: &'a Result<PathBuf, String>,
   pub dotenv: &'a Map<String, String>,
 }
 
@@ -92,6 +98,12 @@ pub fn os_family(_context: &FunctionContext) -> Result<String, String> {
   Ok(target::os_family().to_string())
 }
 
+pub fn invocation_directory(context: &FunctionContext) -> Result<String, String> {
+  context.invocation_directory.clone()
+    .and_then(|s| Platform::to_shell_path(&s)
+      .map_err(|e| format!("Error getting shell path: {}", e)))
+}
+
 pub fn env_var(context: &FunctionContext, key: &str) -> Result<String, String> {
   use std::env::VarError::*;
 

src/justfile.rs

@@ -1,3 +1,5 @@
+use std::path::PathBuf;
+
 use common::*;
 
 use edit_distance::edit_distance;
@@ -42,6 +44,7 @@ impl<'a, 'b> Justfile<'a> where 'a: 'b {
 
   pub fn run(
     &'a self,
+    invocation_directory: Result<PathBuf, String>,
     arguments:     &[&'a str],
     configuration: &Configuration<'a>,
   ) -> RunResult<'a, ()> {
@@ -57,6 +60,7 @@ impl<'a, 'b> Justfile<'a> where 'a: 'b {
 
     let scope = AssignmentEvaluator::evaluate_assignments(
       &self.assignments,
+      &invocation_directory,
       &dotenv,
       &configuration.overrides,
       configuration.quiet,
@@ -115,14 +119,15 @@ impl<'a, 'b> Justfile<'a> where 'a: 'b {
 
     let mut ran = empty();
     for (recipe, arguments) in grouped {
-      self.run_recipe(recipe, arguments, &scope, &dotenv, configuration, &mut ran)?
+      self.run_recipe(&invocation_directory, recipe, arguments, &scope, &dotenv, configuration, &mut ran)?
     }
 
     Ok(())
   }
 
   fn run_recipe<'c>(
     &'c self,
+    invocation_directory: &Result<PathBuf, String>,
     recipe:        &Recipe<'a>,
     arguments:     &[&'a str],
     scope:         &Map<&'c str, String>,
@@ -132,10 +137,10 @@ impl<'a, 'b> Justfile<'a> where 'a: 'b {
   ) -> RunResult<()> {
     for dependency_name in &recipe.dependencies {
       if !ran.contains(dependency_name) {
-        self.run_recipe(&self.recipes[dependency_name], &[], scope, dotenv, configuration, ran)?;
+        self.run_recipe(invocation_directory, &self.recipes[dependency_name], &[], scope, dotenv, configuration, ran)?;
       }
     }
-    recipe.run(arguments, scope, dotenv, &self.exports, configuration)?;
+    recipe.run(invocation_directory, arguments, scope, dotenv, &self.exports, configuration)?;
     ran.insert(recipe.name);
     Ok(())
   }
@@ -171,9 +176,13 @@ mod test {
   use testing::parse_success;
   use RuntimeError::*;
 
+  fn no_cwd_err() -> Result<PathBuf, String> {
+    Err(String::from("no cwd in tests"))
+  }
+
   #[test]
   fn unknown_recipes() {
-    match parse_success("a:\nb:\nc:").run(&["a", "x", "y", "z"], &Default::default()).unwrap_err() {
+    match parse_success("a:\nb:\nc:").run(no_cwd_err(), &["a", "x", "y", "z"], &Default::default()).unwrap_err() {
       UnknownRecipes{recipes, suggestion} => {
         assert_eq!(recipes, &["x", "y", "z"]);
         assert_eq!(suggestion, None);
@@ -201,7 +210,7 @@ a:
       x
 ";
 
-    match parse_success(text).run(&["a"], &Default::default()).unwrap_err() {
+    match parse_success(text).run(no_cwd_err(), &["a"], &Default::default()).unwrap_err() {
       Code{recipe, line_number, code} => {
         assert_eq!(recipe, "a");
         assert_eq!(code, 200);
@@ -214,7 +223,7 @@ a:
   #[test]
   fn code_error() {
     match parse_success("fail:\n @exit 100")
-      .run(&["fail"], &Default::default()).unwrap_err() {
+      .run(no_cwd_err(), &["fail"], &Default::default()).unwrap_err() {
       Code{recipe, line_number, code} => {
         assert_eq!(recipe, "fail");
         assert_eq!(code, 100);
@@ -230,7 +239,7 @@ a:
 a return code:
  @x() { {{return}} {{code + "0"}}; }; x"#;
 
-    match parse_success(text).run(&["a", "return", "15"], &Default::default()).unwrap_err() {
+    match parse_success(text).run(no_cwd_err(), &["a", "return", "15"], &Default::default()).unwrap_err() {
       Code{recipe, line_number, code} => {
         assert_eq!(recipe, "a");
         assert_eq!(code, 150);
@@ -242,7 +251,7 @@ a return code:
 
   #[test]
   fn missing_some_arguments() {
-    match parse_success("a b c d:").run(&["a", "b", "c"], &Default::default()).unwrap_err() {
+    match parse_success("a b c d:").run(no_cwd_err(), &["a", "b", "c"], &Default::default()).unwrap_err() {
       ArgumentCountMismatch{recipe, found, min, max} => {
         assert_eq!(recipe, "a");
         assert_eq!(found, 2);
@@ -255,7 +264,7 @@ a return code:
 
   #[test]
   fn missing_some_arguments_variadic() {
-    match parse_success("a b c +d:").run(&["a", "B", "C"], &Default::default()).unwrap_err() {
+    match parse_success("a b c +d:").run(no_cwd_err(), &["a", "B", "C"], &Default::default()).unwrap_err() {
       ArgumentCountMismatch{recipe, found, min, max} => {
         assert_eq!(recipe, "a");
         assert_eq!(found, 2);
@@ -269,7 +278,7 @@ a return code:
   #[test]
   fn missing_all_arguments() {
     match parse_success("a b c d:\n echo {{b}}{{c}}{{d}}")
-          .run(&["a"], &Default::default()).unwrap_err() {
+          .run(no_cwd_err(), &["a"], &Default::default()).unwrap_err() {
       ArgumentCountMismatch{recipe, found, min, max} => {
         assert_eq!(recipe, "a");
         assert_eq!(found, 0);
@@ -282,7 +291,7 @@ a return code:
 
   #[test]
   fn missing_some_defaults() {
-    match parse_success("a b c d='hello':").run(&["a", "b"], &Default::default()).unwrap_err() {
+    match parse_success("a b c d='hello':").run(no_cwd_err(), &["a", "b"], &Default::default()).unwrap_err() {
       ArgumentCountMismatch{recipe, found, min, max} => {
         assert_eq!(recipe, "a");
         assert_eq!(found, 1);
@@ -295,7 +304,7 @@ a return code:
 
   #[test]
   fn missing_all_defaults() {
-    match parse_success("a b c='r' d='h':").run(&["a"], &Default::default()).unwrap_err() {
+    match parse_success("a b c='r' d='h':").run(no_cwd_err(), &["a"], &Default::default()).unwrap_err() {
       ArgumentCountMismatch{recipe, found, min, max} => {
         assert_eq!(recipe, "a");
         assert_eq!(found, 0);
@@ -312,7 +321,7 @@ a return code:
     configuration.overrides.insert("foo", "bar");
     configuration.overrides.insert("baz", "bob");
     match parse_success("a:\n echo {{`f() { return 100; }; f`}}")
-          .run(&["a"], &configuration).unwrap_err() {
+          .run(no_cwd_err(), &["a"], &configuration).unwrap_err() {
       UnknownOverrides{overrides} => {
         assert_eq!(overrides, &["baz", "foo"]);
       },
@@ -337,7 +346,7 @@ wut:
       ..Default::default()
     };
 
-    match parse_success(text).run(&["wut"], &configuration).unwrap_err() {
+    match parse_success(text).run(no_cwd_err(), &["wut"], &configuration).unwrap_err() {
       Code{code: _, line_number, recipe} => {
         assert_eq!(recipe, "wut");
         assert_eq!(line_number, Some(8));

src/platform.rs

@@ -15,8 +15,12 @@ pub trait PlatformInterface {
 
   /// Extract the signal from a process exit status, if it was terminated by a signal
   fn signal_from_exit_status(exit_status: process::ExitStatus) -> Option<i32>;
+
+  /// Translate a path from a "native" path to a path the interpreter expects
+  fn to_shell_path(path: &Path) -> Result<String, String>;
 }
 
+
 #[cfg(unix)]
 impl PlatformInterface for Platform {
   fn make_shebang_command(path: &Path, _command: &str, _argument: Option<&str>)
@@ -44,6 +48,12 @@ impl PlatformInterface for Platform {
     use std::os::unix::process::ExitStatusExt;
     exit_status.signal()
   }
+
+  fn to_shell_path(path: &Path) -> Result<String, String> {
+    path.to_str().map(str::to_string)
+      .ok_or_else(|| String::from(
+        "Error getting current directory: unicode decode error"))
+  }
 }
 
 #[cfg(windows)]
@@ -75,4 +85,12 @@ impl PlatformInterface for Platform {
     // from a windows process exit status, so just return None
     None
   }
+
+  fn to_shell_path(path: &Path) -> Result<String, String> {
+    // Translate path from windows style to unix style
+    let mut cygpath = Command::new("cygpath");
+    cygpath.arg("--unix");
+    cygpath.arg(path);
+    brev::output(cygpath).map_err(|e| format!("Error converting shell path: {}", e))
+  }
 }

src/recipe.rs

@@ -1,5 +1,6 @@
 use common::*;
 
+use std::path::PathBuf;
 use std::process::{ExitStatus, Command, Stdio};
 
 use platform::{Platform, PlatformInterface};
@@ -50,6 +51,7 @@ impl<'a> Recipe<'a> {
 
   pub fn run(
     &self,
+    invocation_directory: &Result<PathBuf, String>,
     arguments:     &[&'a str],
     scope:         &Map<&'a str, String>,
     dotenv:        &Map<String, String>,
@@ -86,6 +88,7 @@ impl<'a> Recipe<'a> {
 
     let mut evaluator = AssignmentEvaluator {
       assignments: &empty(),
+      invocation_directory,
       dry_run:     configuration.dry_run,
       evaluated:   empty(),
       overrides:   &empty(),

src/run.rs

@@ -47,6 +47,9 @@ pub fn run() {
   #[cfg(windows)]
   enable_ansi_support().ok();
 
+  let invocation_directory = env::current_dir()
+    .map_err(|e| format!("Error getting current directory: {}", e));
+
   let matches = App::new(env!("CARGO_PKG_NAME"))
     .version(concat!("v", env!("CARGO_PKG_VERSION")))
     .author(env!("CARGO_PKG_AUTHORS"))
@@ -354,7 +357,11 @@ pub fn run() {
     overrides,
   };
 
-  if let Err(run_error) = justfile.run(&arguments, &configuration) {
+  if let Err(run_error) = justfile.run(
+    invocation_directory,
+    &arguments,
+    &configuration)
+  {
     if !configuration.quiet {
       if color.stderr().active() {
         eprintln!("{:#}", run_error);