feat: show request items separators in naked invocation usage

httpie/cli/argparser.py

@@ -595,6 +595,19 @@ def print_usage(self, file):
         usage_text.append(rich_help.to_usage(self.spec, whitelist=whitelist))
         self.env.rich_error_console.print(usage_text)
 
+        from rich.console import Group
+        cheatsheet_heading = Text('request items', style='bold')
+        cheatsheet_heading.append(
+            " (common separators, run 'http --help' for all options):",
+            style='default',
+        )
+        self.env.rich_error_console.print(
+            Group(
+                cheatsheet_heading,
+                rich_help.to_request_items_cheatsheet(),
+            )
+        )
+
     def error(self, message):
         """Prints a usage message incorporating the message to stderr and
         exits."""

httpie/output/ui/rich_help.py

@@ -8,7 +8,14 @@
 from rich.table import Table
 from rich.text import Text
 
-from httpie.cli.constants import SEPARATOR_GROUP_ALL_ITEMS
+from httpie.cli.constants import (
+    SEPARATOR_DATA_RAW_JSON,
+    SEPARATOR_DATA_STRING,
+    SEPARATOR_FILE_UPLOAD,
+    SEPARATOR_GROUP_ALL_ITEMS,
+    SEPARATOR_HEADER,
+    SEPARATOR_QUERY_PARAM,
+)
 from httpie.cli.options import Argument, ParserSpec, Qualifiers
 from httpie.output.ui.palette import GenericColor
 
@@ -123,6 +130,23 @@ def to_usage(
     return text
 
 
+REQUEST_ITEMS_CHEATSHEET = [
+    (SEPARATOR_QUERY_PARAM, 'Query params'),
+    (SEPARATOR_DATA_STRING, 'Data fields (string)'),
+    (SEPARATOR_DATA_RAW_JSON, 'Data fields (raw JSON)'),
+    (SEPARATOR_FILE_UPLOAD, 'File upload'),
+    (SEPARATOR_HEADER, 'HTTP headers'),
+]
+
+
+def to_request_items_cheatsheet() -> RenderableType:
+    text = Text()
+    for separator, description in REQUEST_ITEMS_CHEATSHEET:
+        text.append(f'    {separator:<6}{description}\n', style=STYLE_METAVAR)
+    text.rstrip()
+    return text
+
+
 # This part is loosely based on the rich-click's help message
 # generation.
 def to_help_message(

tests/test_cli_ui.py

@@ -6,6 +6,12 @@
 NAKED_BASE_TEMPLATE = """\
 usage:
     http {extra_args}[METHOD] URL [REQUEST_ITEM ...]
+request items (common separators, run 'http --help' for all options):
+    ==    Query params
+    =     Data fields (string)
+    :=    Data fields (raw JSON)
+    @     File upload
+    :     HTTP headers
 
 error:
     {error_msg}