make argument placeholders optional (#1317)

* support argument placeholder

* default to true

* fix review

* completion: handle cursor placement

Correctly handles cursor placement after a completion when placeholders are disabled but snippets are not.

---------

Co-authored-by: Lee Cannon <[email protected]>

Author: 2 people

README.md

@@ -63,6 +63,7 @@ The following options are currently available.
 | Option | Type | Default value | What it Does |
 | --- | --- | --- | --- |
 | `enable_snippets` | `bool` | `true` | Enables snippet completions when the client also supports them |
+| `enable_argument_placeholders` | `bool` | `true` | Whether to enable function argument placeholder completions |
 | `enable_ast_check_diagnostics` | `bool` | `true` | Whether to enable ast-check diagnostics |
 | `enable_autofix` | `bool` | `true` | Whether to automatically fix errors on save. Currently supports adding and removing discards. |
 | `enable_import_embedfile_argument_completions` | `bool` | `true` | Whether to enable import/embedFile argument completions |
@@ -149,7 +150,7 @@ You can use zls as a library! [Check out this demo repo](https://github.com/zigt
 
 ## Quick Thanks :)
 
-We'd like to take a second to thank all our awesome [contributors](https://github.com/zigtools/zls/graphs/contributors) and donators/backers/sponsors; if you have time or money to spare, consider partaking in either of these options - they help keep zls awesome for everyone! 
+We'd like to take a second to thank all our awesome [contributors](https://github.com/zigtools/zls/graphs/contributors) and donators/backers/sponsors; if you have time or money to spare, consider partaking in either of these options - they help keep zls awesome for everyone!
 
 [![OpenCollective Backers](https://opencollective.com/zigtools/backers.svg?width=890&limit=1000)](https://opencollective.com/zigtools#category-CONTRIBUTE)
 

schema.json

@@ -9,6 +9,11 @@
             "type": "boolean",
             "default": "true"
         },
+        "enable_argument_placeholders": {
+            "description": "Whether to enable function argument placeholder completions",
+            "type": "boolean",
+            "default": "true"
+        },
         "enable_ast_check_diagnostics": {
             "description": "Whether to enable ast-check diagnostics",
             "type": "boolean",

src/Config.zig

@@ -7,6 +7,9 @@
 /// Enables snippet completions when the client also supports them
 enable_snippets: bool = true,
 
+/// Whether to enable function argument placeholder completions
+enable_argument_placeholders: bool = true,
+
 /// Whether to enable ast-check diagnostics
 enable_ast_check_diagnostics: bool = true,
 

src/config_gen/config.json

@@ -6,6 +6,12 @@
             "type": "bool",
             "default": "true"
         },
+        {
+            "name": "enable_argument_placeholders",
+            "description": "Whether to enable function argument placeholder completions",
+            "type": "bool",
+            "default": "true"
+        },
         {
             "name": "enable_ast_check_diagnostics",
             "description": "Whether to enable ast-check diagnostics",
@@ -168,4 +174,4 @@
             "default": "null"
         }
     ]
-}
+}

src/features/completions.zig

@@ -195,11 +195,33 @@ fn nodeToCompletion(
             const func = tree.fullFnProto(&buf, node).?;
             if (func.name_token) |name_token| {
                 const use_snippets = server.config.enable_snippets and server.client_capabilities.supports_snippets;
-                const insert_text = if (use_snippets) blk: {
-                    const skip_self_param = !(parent_is_type_val orelse true) and
-                        try analyser.hasSelfParam(handle, func);
-                    break :blk try Analyser.getFunctionSnippet(arena, tree, func, skip_self_param);
-                } else tree.tokenSlice(func.name_token.?);
+
+                const insert_text = blk: {
+                    const func_name = tree.tokenSlice(func.name_token.?);
+
+                    if (!use_snippets) break :blk func_name;
+
+                    const skip_self_param = !(parent_is_type_val orelse true) and try analyser.hasSelfParam(handle, func);
+
+                    const use_placeholders = server.config.enable_argument_placeholders;
+                    if (use_placeholders) break :blk try Analyser.getFunctionSnippet(arena, tree, func, skip_self_param);
+
+                    switch (func.ast.params.len) {
+                        // No arguments, leave cursor at the end
+                        0 => break :blk try std.fmt.allocPrint(arena, "{s}()", .{func_name}),
+                        1 => {
+                            if (skip_self_param) {
+                                // The one argument is a self parameter, leave cursor at the end
+                                break :blk try std.fmt.allocPrint(arena, "{s}()", .{func_name});
+                            }
+
+                            // Non-self parameter, leave the cursor in the parentheses
+                            break :blk try std.fmt.allocPrint(arena, "{s}(${{1:}})", .{func_name});
+                        },
+                        // Atleast one non-self parameter, leave the cursor in the parentheses
+                        else => break :blk try std.fmt.allocPrint(arena, "{s}(${{1:}})", .{func_name}),
+                    }
+                };
 
                 const is_type_function = Analyser.isTypeFunction(handle.tree, func);