Allow duplicate recipes

README.md

@@ -521,13 +521,14 @@ foo:
 
 #### Table of Settings
 
-| Name                   | Value              | Description                                                    |
-| ---------------------- | ------------------ | -------------------------------------------------------------- |
-| `dotenv-load`          | boolean            | Load a `.env` file, if present.                                |
-| `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.                    |
+| Name                      | Value              | Description                                                                                   |
+| ------------------------- | ------------------ | --------------------------------------------------------------------------------------------- |
+| `allow-duplicate-recipes` | boolean            | Allow recipes appearing later in a `justfile` to override earlier recipes with the same name. |
+| `dotenv-load`             | boolean            | Load a `.env` file, if present.                                                               |
+| `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.                                                   |
 
 Boolean settings can be written as:
 
@@ -541,6 +542,25 @@ Which is equivalent to:
 set NAME := true
 ```
 
+#### Allow Duplicate Recipes
+
+If `allow-duplicate-recipes` is `true`, defining multiple recipes with the same name is not an error, and the last definition is used. Defaults to `false`.
+
+```make
+set allow-duplicate-recipes
+
+@foo:
+  echo foo
+
+@foo:
+  echo bar
+```
+
+```sh
+$ just foo
+bar
+```
+
 #### Dotenv Load
 
 If `dotenv-load` is `true`, a `.env` file will be loaded if present. Defaults to `true`.

src/analyzer.rs

@@ -16,6 +16,8 @@ impl<'src> Analyzer<'src> {
   }
 
   pub(crate) fn justfile(mut self, ast: Ast<'src>) -> CompileResult<'src, Justfile<'src>> {
+    let mut recipes = Vec::new();
+
     for item in ast.items {
       match item {
         Item::Alias(alias) => {
@@ -29,7 +31,7 @@ impl<'src> Analyzer<'src> {
         Item::Comment(_) => (),
         Item::Recipe(recipe) => {
           self.analyze_recipe(&recipe)?;
-          self.recipes.insert(recipe);
+          recipes.push(recipe);
         }
         Item::Set(set) => {
           self.analyze_set(&set)?;
@@ -38,31 +40,13 @@ impl<'src> Analyzer<'src> {
       }
     }
 
-    let assignments = self.assignments;
-
-    AssignmentResolver::resolve_assignments(&assignments)?;
-
-    let recipes = RecipeResolver::resolve_recipes(self.recipes, &assignments)?;
-
-    for recipe in recipes.values() {
-      for parameter in &recipe.parameters {
-        if assignments.contains_key(parameter.name.lexeme()) {
-          return Err(parameter.name.token().error(ParameterShadowsVariable {
-            parameter: parameter.name.lexeme(),
-          }));
-        }
-      }
-    }
-
-    let mut aliases = Table::new();
-    while let Some(alias) = self.aliases.pop() {
-      aliases.insert(Self::resolve_alias(&recipes, alias)?);
-    }
-
     let mut settings = Settings::new();
 
     for (_, set) in self.sets {
       match set.value {
+        Setting::AllowDuplicateRecipes(allow_duplicate_recipes) => {
+          settings.allow_duplicate_recipes = allow_duplicate_recipes;
+        }
         Setting::DotenvLoad(dotenv_load) => {
           settings.dotenv_load = Some(dotenv_load);
         }
@@ -82,6 +66,39 @@ impl<'src> Analyzer<'src> {
       }
     }
 
+    let assignments = self.assignments;
+
+    AssignmentResolver::resolve_assignments(&assignments)?;
+
+    for recipe in recipes {
+      if let Some(original) = self.recipes.get(recipe.name.lexeme()) {
+        if !settings.allow_duplicate_recipes {
+          return Err(recipe.name.token().error(DuplicateRecipe {
+            recipe: original.name(),
+            first: original.line_number(),
+          }));
+        }
+      }
+      self.recipes.insert(recipe);
+    }
+
+    let recipes = RecipeResolver::resolve_recipes(self.recipes, &assignments)?;
+
+    for recipe in recipes.values() {
+      for parameter in &recipe.parameters {
+        if assignments.contains_key(parameter.name.lexeme()) {
+          return Err(parameter.name.token().error(ParameterShadowsVariable {
+            parameter: parameter.name.lexeme(),
+          }));
+        }
+      }
+    }
+
+    let mut aliases = Table::new();
+    while let Some(alias) = self.aliases.pop() {
+      aliases.insert(Self::resolve_alias(&recipes, alias)?);
+    }
+
     Ok(Justfile {
       warnings: ast.warnings,
       first: recipes
@@ -102,13 +119,6 @@ impl<'src> Analyzer<'src> {
   }
 
   fn analyze_recipe(&self, recipe: &UnresolvedRecipe<'src>) -> CompileResult<'src, ()> {
-    if let Some(original) = self.recipes.get(recipe.name.lexeme()) {
-      return Err(recipe.name.token().error(DuplicateRecipe {
-        recipe: original.name(),
-        first: original.line_number(),
-      }));
-    }
-
     let mut parameters = BTreeSet::new();
     let mut passed_default = false;
 

src/keyword.rs

@@ -4,6 +4,7 @@ use crate::common::*;
 #[strum(serialize_all = "kebab_case")]
 pub(crate) enum Keyword {
   Alias,
+  AllowDuplicateRecipes,
   DotenvLoad,
   Else,
   Export,

src/node.rs

@@ -221,7 +221,7 @@ impl<'src> Node<'src> for Set<'src> {
     set.push_mut(self.name.lexeme().replace('-', "_"));
 
     match &self.value {
-      DotenvLoad(value) | Export(value) | PositionalArguments(value) | WindowsPowerShell(value) => {
+      AllowDuplicateRecipes(value) | DotenvLoad(value) | Export(value) | PositionalArguments(value) | WindowsPowerShell(value) => {
         set.push_mut(value.to_string());
       }
       Shell(setting::Shell { command, arguments }) => {

src/parser.rs

@@ -729,7 +729,13 @@ impl<'tokens, 'src> Parser<'tokens, 'src> {
     let name = Name::from_identifier(self.presume(Identifier)?);
     let lexeme = name.lexeme();
 
-    if Keyword::DotenvLoad == lexeme {
+    if Keyword::AllowDuplicateRecipes == lexeme {
+      let value = self.parse_set_bool()?;
+      return Ok(Set {
+        value: Setting::AllowDuplicateRecipes(value),
+        name,
+      });
+    } else if Keyword::DotenvLoad == lexeme {
       let value = self.parse_set_bool()?;
       return Ok(Set {
         value: Setting::DotenvLoad(value),
@@ -1714,6 +1720,12 @@ mod tests {
     tree: (justfile (set dotenv_load true)),
   }
 
+  test! {
+    name: set_allow_duplicate_recipes_implicit,
+    text: "set allow-duplicate-recipes",
+    tree: (justfile (set allow_duplicate_recipes true)),
+  }
+
   test! {
     name: set_dotenv_load_true,
     text: "set dotenv-load := true",

src/setting.rs

@@ -2,6 +2,7 @@ use crate::common::*;
 
 #[derive(Debug, Clone)]
 pub(crate) enum Setting<'src> {
+  AllowDuplicateRecipes(bool),
   DotenvLoad(bool),
   Export(bool),
   PositionalArguments(bool),
@@ -18,7 +19,8 @@ pub(crate) struct Shell<'src> {
 impl<'src> Display for Setting<'src> {
   fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
     match self {
-      Setting::DotenvLoad(value)
+      Setting::AllowDuplicateRecipes(value)
+      | Setting::DotenvLoad(value)
       | Setting::Export(value)
       | Setting::PositionalArguments(value)
       | Setting::WindowsPowerShell(value) => write!(f, "{}", value),

src/settings.rs

@@ -7,6 +7,7 @@ pub(crate) const WINDOWS_POWERSHELL_ARGS: &[&str] = &["-NoLogo", "-Command"];
 
 #[derive(Debug, PartialEq, Serialize)]
 pub(crate) struct Settings<'src> {
+  pub(crate) allow_duplicate_recipes: bool,
   pub(crate) dotenv_load: Option<bool>,
   pub(crate) export: bool,
   pub(crate) positional_arguments: bool,
@@ -17,6 +18,7 @@ pub(crate) struct Settings<'src> {
 impl<'src> Settings<'src> {
   pub(crate) fn new() -> Settings<'src> {
     Settings {
+      allow_duplicate_recipes: false,
       dotenv_load: None,
       export: false,
       positional_arguments: false,

tests/allow_duplicate_recipes.rs

@@ -0,0 +1,38 @@
+use crate::common::*;
+
+#[test]
+fn allow_duplicate_recipes() {
+  Test::new()
+    .justfile(
+      "
+      b:
+        echo foo
+      b:
+        echo bar
+
+      set allow-duplicate-recipes
+    ",
+    )
+    .stdout("bar\n")
+    .stderr("echo bar\n")
+    .run();
+}
+
+#[test]
+fn allow_duplicate_recipes_with_args() {
+  Test::new()
+    .justfile(
+      "
+      b a:
+        echo foo
+      b c d:
+        echo bar {{c}} {{d}}
+
+      set allow-duplicate-recipes
+    ",
+    )
+    .args(&["b", "one", "two"])
+    .stdout("bar one two\n")
+    .stderr("echo bar one two\n")
+    .run();
+}