From 368ab10efee349c86d12be58ec01485a805d697f Mon Sep 17 00:00:00 2001
From: Gwendolyn <me@gwendolyn.dev>
Date: Wed, 24 Jul 2024 21:22:36 +0200
Subject: [PATCH] use block signature instead of decl signature for generating
 help output and when parsing calls

---
 crates/nu-engine/src/documentation.rs |  4 +-
 crates/nu-parser/src/parser.rs        |  7 ++-
 tests/shell/mod.rs                    | 66 +++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/crates/nu-engine/src/documentation.rs b/crates/nu-engine/src/documentation.rs
index a0dee3d343..2bbb146398 100644
--- a/crates/nu-engine/src/documentation.rs
+++ b/crates/nu-engine/src/documentation.rs
@@ -21,7 +21,9 @@ pub fn get_full_help(
     };
 
     let stack = &mut stack.start_capture();
-    let signature = command.signature().update_from_command(command);
+    let signature = engine_state
+        .get_signature(command)
+        .update_from_command(command);
 
     get_documentation(
         &signature,
diff --git a/crates/nu-parser/src/parser.rs b/crates/nu-parser/src/parser.rs
index 1fb0aee01d..cdcb4ed5ca 100644
--- a/crates/nu-parser/src/parser.rs
+++ b/crates/nu-parser/src/parser.rs
@@ -954,7 +954,12 @@ pub fn parse_internal_call(
     let _ = working_set.add_span(call.head);
 
     let decl = working_set.get_decl(decl_id);
-    let signature = decl.signature();
+    let signature = if let Some(block_id) = decl.block_id() {
+        let block = working_set.get_block(block_id);
+        *block.signature.clone()
+    } else {
+        decl.signature()
+    };
     let output = signature.get_output_type();
 
     // storing the var ID for later due to borrowing issues
diff --git a/tests/shell/mod.rs b/tests/shell/mod.rs
index 62f79a59c1..bedfe8304e 100644
--- a/tests/shell/mod.rs
+++ b/tests/shell/mod.rs
@@ -334,3 +334,69 @@ fn source_empty_file() {
         assert!(actual.out.is_empty());
     })
 }
+
+#[test]
+fn main_script_help_uses_script_name1() {
+    // Note: this test is somewhat fragile and might need to be adapted if the usage help message changes
+    Playground::setup("main_filename", |dirs, sandbox| {
+        sandbox.mkdir("main_filename");
+        sandbox.with_files(&[FileWithContent(
+            "script.nu",
+            r#"def main [] {}
+            "#,
+        )]);
+        let actual = nu!(cwd: dirs.test(), pipeline("nu script.nu --help"));
+        assert!(actual.out.contains("> script.nu"));
+        assert!(!actual.out.contains("> main"));
+    })
+}
+
+#[test]
+fn main_script_help_uses_script_name2() {
+    // Note: this test is somewhat fragile and might need to be adapted if the usage help message changes
+    Playground::setup("main_filename", |dirs, sandbox| {
+        sandbox.mkdir("main_filename");
+        sandbox.with_files(&[FileWithContent(
+            "script.nu",
+            r#"def main [foo: string] {}
+            "#,
+        )]);
+        let actual = nu!(cwd: dirs.test(), pipeline("nu script.nu"));
+        assert!(actual.err.contains("Usage: script.nu"));
+        assert!(!actual.err.contains("Usage: main"));
+    })
+}
+
+#[test]
+fn main_script_subcommand_help_uses_script_name1() {
+    // Note: this test is somewhat fragile and might need to be adapted if the usage help message changes
+    Playground::setup("main_filename", |dirs, sandbox| {
+        sandbox.mkdir("main_filename");
+        sandbox.with_files(&[FileWithContent(
+            "script.nu",
+            r#"def main [] {}
+            def 'main foo' [] {}
+            "#,
+        )]);
+        let actual = nu!(cwd: dirs.test(), pipeline("nu script.nu foo --help"));
+        assert!(actual.out.contains("> script.nu foo"));
+        assert!(!actual.out.contains("> main foo"));
+    })
+}
+
+#[test]
+fn main_script_subcommand_help_uses_script_name2() {
+    // Note: this test is somewhat fragile and might need to be adapted if the usage help message changes
+    Playground::setup("main_filename", |dirs, sandbox| {
+        sandbox.mkdir("main_filename");
+        sandbox.with_files(&[FileWithContent(
+            "script.nu",
+            r#"def main [] {}
+            def 'main foo' [bar: string] {}
+            "#,
+        )]);
+        let actual = nu!(cwd: dirs.test(), pipeline("nu script.nu foo"));
+        assert!(actual.err.contains("Usage: script.nu foo"));
+        assert!(!actual.err.contains("Usage: main foo"));
+    })
+}