add signature information when get help on one command (#7079)

* add signature information when help on one command

* tell user that one command support operated on cell paths

Also, make type output to be more friendly, like `record<>` should just be `record`

And the same to `table<>`, which should be `table`

* simplify code

* don't show signatures for parser keyword

* update comment

* output arg syntax shape as type, so it's the same as describe command

* fix string when no positional args

* update signature body

* update

* add help signature test

* fix arg output format for composed data type like list or record

* fix clippy

* add comment

crates/nu-command/src/bits/bits_.rs

@@ -29,7 +29,13 @@ impl Command for Bits {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Bits.signature(), &Bits.examples(), engine_state, stack),
+            val: get_full_help(
+                &Bits.signature(),
+                &Bits.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/bytes/bytes_.rs

@@ -29,7 +29,13 @@ impl Command for Bytes {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Bytes.signature(), &Bytes.examples(), engine_state, stack),
+            val: get_full_help(
+                &Bytes.signature(),
+                &Bytes.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/conversions/into/command.rs

@@ -29,7 +29,13 @@ impl Command for Into {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Into.signature(), &[], engine_state, stack),
+            val: get_full_help(
+                &Into.signature(),
+                &[],
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/core_commands/export.rs

@@ -45,6 +45,7 @@ impl Command for ExportCommand {
                 &ExportCommand.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/core_commands/help.rs

@@ -1,5 +1,4 @@
 use fancy_regex::Regex;
-use itertools::Itertools;
 use nu_ansi_term::{
     Color::{Default, Red, White},
     Style,
@@ -105,6 +104,7 @@ fn help(
             let mut vals = vec![];
             let decl = engine_state.get_decl(decl_id);
             let sig = decl.signature().update_from_command(decl.borrow());
+            let signatures = sig.to_string();
             let key = sig.name;
             let usage = sig.usage;
             let search_terms = sig.search_terms;
@@ -154,11 +154,11 @@ fn help(
 
                 cols.push("signatures".into());
                 vals.push(Value::String {
-                    val: sig
-                        .input_output_types
-                        .iter()
-                        .map(|(i, o)| format!("{:?} => {:?}", i.to_shape(), o.to_shape()))
-                        .join("\n"),
+                    val: if decl.is_parser_keyword() {
+                        "".to_string()
+                    } else {
+                        signatures
+                    },
                     span: head,
                 });
 
@@ -219,6 +219,7 @@ fn help(
                 let decl = engine_state.get_decl(decl_id);
                 let sig = decl.signature().update_from_command(decl.borrow());
 
+                let signatures = sig.to_string();
                 let key = sig.name;
                 let usage = sig.usage;
                 let search_terms = sig.search_terms;
@@ -249,11 +250,11 @@ fn help(
 
                 cols.push("signatures".into());
                 vals.push(Value::String {
-                    val: sig
-                        .input_output_types
-                        .iter()
-                        .map(|(i, o)| format!("{:?} => {:?}", i.to_shape(), o.to_shape()))
-                        .join("\n"),
+                    val: if decl.is_parser_keyword() {
+                        "".to_string()
+                    } else {
+                        signatures
+                    },
                     span: head,
                 });
 
@@ -290,9 +291,9 @@ fn help(
             let output = engine_state
                 .get_signatures_with_examples(false)
                 .iter()
-                .filter(|(signature, _, _, _)| signature.name == name)
-                .map(|(signature, examples, _, _)| {
-                    get_full_help(signature, examples, engine_state, stack)
+                .filter(|(signature, _, _, _, _)| signature.name == name)
+                .map(|(signature, examples, _, _, is_parser_keyword)| {
+                    get_full_help(signature, examples, engine_state, stack, *is_parser_keyword)
                 })
                 .collect::<Vec<String>>();
 

crates/nu-command/src/core_commands/overlay/command.rs

@@ -38,7 +38,13 @@ impl Command for Overlay {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Overlay.signature(), &[], engine_state, stack),
+            val: get_full_help(
+                &Overlay.signature(),
+                &[],
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/date/date_.rs

@@ -53,7 +53,13 @@ fn date(
     let head = call.head;
 
     Ok(Value::String {
-        val: get_full_help(&Date.signature(), &Date.examples(), engine_state, stack),
+        val: get_full_help(
+            &Date.signature(),
+            &Date.examples(),
+            engine_state,
+            stack,
+            false,
+        ),
         span: head,
     }
     .into_pipeline_data())

crates/nu-command/src/env/config/config_.rs

@@ -34,6 +34,7 @@ impl Command for ConfigMeta {
                 &ConfigMeta.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/filters/roll/roll_.rs

@@ -31,7 +31,13 @@ impl Command for Roll {
         _input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Roll.signature(), &Roll.examples(), engine_state, stack),
+            val: get_full_help(
+                &Roll.signature(),
+                &Roll.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/formats/from/command.rs

@@ -27,7 +27,13 @@ impl Command for From {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, ShellError> {
         Ok(Value::String {
-            val: get_full_help(&From.signature(), &From.examples(), engine_state, stack),
+            val: get_full_help(
+                &From.signature(),
+                &From.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/formats/to/command.rs

@@ -27,7 +27,13 @@ impl Command for To {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, ShellError> {
         Ok(Value::String {
-            val: get_full_help(&To.signature(), &To.examples(), engine_state, stack),
+            val: get_full_help(
+                &To.signature(),
+                &To.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/hash/hash_.rs

@@ -27,7 +27,13 @@ impl Command for Hash {
         _input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Self.signature(), &Self.examples(), engine_state, stack),
+            val: get_full_help(
+                &Self.signature(),
+                &Self.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/math/math_.rs

@@ -34,6 +34,7 @@ impl Command for MathCommand {
                 &MathCommand.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/network/url/url_.rs

@@ -35,7 +35,13 @@ impl Command for Url {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Url.signature(), &Url.examples(), engine_state, stack),
+            val: get_full_help(
+                &Url.signature(),
+                &Url.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/src/path/path_.rs

@@ -49,6 +49,7 @@ the path literal."#
                 &PathCommand.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/platform/reedline_commands/keybindings.rs

@@ -38,6 +38,7 @@ impl Command for Keybindings {
                 &Keybindings.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/random/random_.rs

@@ -38,6 +38,7 @@ impl Command for RandomCommand {
                 &RandomCommand.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/strings/split/command.rs

@@ -34,6 +34,7 @@ impl Command for SplitCommand {
                 &SplitCommand.examples(),
                 engine_state,
                 stack,
+                self.is_parser_keyword(),
             ),
             span: call.head,
         }

crates/nu-command/src/strings/str_/case/str_.rs

@@ -29,7 +29,13 @@ impl Command for Str {
         _input: PipelineData,
     ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
         Ok(Value::String {
-            val: get_full_help(&Str.signature(), &Str.examples(), engine_state, stack),
+            val: get_full_help(
+                &Str.signature(),
+                &Str.examples(),
+                engine_state,
+                stack,
+                self.is_parser_keyword(),
+            ),
             span: call.head,
         }
         .into_pipeline_data())

crates/nu-command/tests/commands/help.rs

@@ -14,3 +14,15 @@ fn help_commands_length() {
     let is_positive = output_int.is_positive();
     assert!(is_positive);
 }
+
+#[test]
+fn help_shows_signature() {
+    let actual = nu!(cwd: ".", pipeline("help str distance"));
+    assert!(actual
+        .out
+        .contains("<string> | str distance <string> -> <int>"));
+
+    // don't show signature for parser keyword
+    let actual = nu!(cwd: ".", pipeline("help alias"));
+    assert!(!actual.out.contains("Signatures"));
+}

crates/nu-command/tests/commands/reject.rs

@@ -92,7 +92,7 @@ fn reject_record_from_raw_eval() {
         )
     );
 
-    assert!(actual.out.contains("record<>"));
+    assert!(actual.out.contains("record"));
 }
 
 #[test]