From af54dafa77f3f7c4ea0c6a519c252cd38704b588 Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Mon, 9 Jan 2023 16:59:02 -0800
Subject: [PATCH] Allow recipe parameters to shadow variables (#1480)

---
 src/analyzer.rs               | 20 --------------------
 src/compile_error.rs          |  6 ------
 src/compile_error_kind.rs     |  3 ---
 tests/lib.rs                  |  1 +
 tests/misc.rs                 | 13 -------------
 tests/shadowing_parameters.rs | 23 +++++++++++++++++++++++
 6 files changed, 24 insertions(+), 42 deletions(-)
 create mode 100644 tests/shadowing_parameters.rs

diff --git a/src/analyzer.rs b/src/analyzer.rs
index 53247bb..c8ee53e 100644
--- a/src/analyzer.rs
+++ b/src/analyzer.rs
@@ -97,16 +97,6 @@ impl<'src> Analyzer<'src> {
 
     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)?);
@@ -316,16 +306,6 @@ mod tests {
     kind:   DuplicateParameter{recipe: "a", parameter: "b"},
   }
 
-  analysis_error! {
-    name:   parameter_shadows_variable,
-    input:  "foo := \"h\"\na foo:",
-    offset:  13,
-    line:   1,
-    column: 2,
-    width:  3,
-    kind:   ParameterShadowsVariable{parameter: "foo"},
-  }
-
   analysis_error! {
     name:   duplicate_recipe,
     input:  "a:\nb:\na:",
diff --git a/src/compile_error.rs b/src/compile_error.rs
index c7dcbdf..5a90b52 100644
--- a/src/compile_error.rs
+++ b/src/compile_error.rs
@@ -226,12 +226,6 @@ impl Display for CompileError<'_> {
       ParameterFollowsVariadicParameter { parameter } => {
         write!(f, "Parameter `{parameter}` follows variadic parameter")?;
       }
-      ParameterShadowsVariable { parameter } => {
-        write!(
-          f,
-          "Parameter `{parameter}` shadows variable of the same name",
-        )?;
-      }
       ParsingRecursionDepthExceeded => {
         write!(f, "Parsing recursion depth exceeded")?;
       }
diff --git a/src/compile_error_kind.rs b/src/compile_error_kind.rs
index 8c1fcdf..acd8b2f 100644
--- a/src/compile_error_kind.rs
+++ b/src/compile_error_kind.rs
@@ -79,9 +79,6 @@ pub(crate) enum CompileErrorKind<'src> {
   ParameterFollowsVariadicParameter {
     parameter: &'src str,
   },
-  ParameterShadowsVariable {
-    parameter: &'src str,
-  },
   ParsingRecursionDepthExceeded,
   RequiredParameterFollowsDefaultParameter {
     parameter: &'src str,
diff --git a/tests/lib.rs b/tests/lib.rs
index ce24668..cceacc8 100644
--- a/tests/lib.rs
+++ b/tests/lib.rs
@@ -72,6 +72,7 @@ mod recursion_limit;
 mod regexes;
 mod run;
 mod search;
+mod shadowing_parameters;
 mod shebang;
 mod shell;
 mod show;
diff --git a/tests/misc.rs b/tests/misc.rs
index 4a903bc..6c2fb93 100644
--- a/tests/misc.rs
+++ b/tests/misc.rs
@@ -1151,19 +1151,6 @@ c: b a
   stdout:   "",
 }
 
-test! {
-  name:     parameter_shadows_variable,
-  justfile: "FOO := 'hello'\na FOO:",
-  args:     ("a"),
-  stdout:   "",
-  stderr:   "error: Parameter `FOO` shadows variable of the same name
-  |
-2 | a FOO:
-  |   ^^^
-",
-  status:   EXIT_FAILURE,
-}
-
 test! {
   name:     unknown_function_in_assignment,
   justfile: r#"foo := foo() + "hello"
diff --git a/tests/shadowing_parameters.rs b/tests/shadowing_parameters.rs
new file mode 100644
index 0000000..3778996
--- /dev/null
+++ b/tests/shadowing_parameters.rs
@@ -0,0 +1,23 @@
+test! {
+  name:     parameter_may_shadow_variable,
+  justfile: "FOO := 'hello'\na FOO:\n echo {{FOO}}\n",
+  args:     ("a", "bar"),
+  stdout:   "bar\n",
+  stderr:   "echo bar\n",
+}
+
+test! {
+  name:     shadowing_parameters_do_not_change_environment,
+  justfile: "export FOO := 'hello'\na FOO:\n echo $FOO\n",
+  args:     ("a", "bar"),
+  stdout:   "hello\n",
+  stderr:   "echo $FOO\n",
+}
+
+test! {
+  name:     exporting_shadowing_parameters_does_change_environment,
+  justfile: "export FOO := 'hello'\na $FOO:\n echo $FOO\n",
+  args:     ("a", "bar"),
+  stdout:   "bar\n",
+  stderr:   "echo $FOO\n",
+}