Add netcoredbg debug adapter, dotnet locator, and runnables

README.md

@@ -2,6 +2,63 @@
 
 A [C#](https://learn.microsoft.com/en-us/dotnet/csharp/) extension for [Zed](https://zed.dev).
 
+## Debugging
+
+The extension provides the [netcoredbg](https://github.com/Samsung/netcoredbg)
+debug adapter. The adapter binary is downloaded automatically on first use; to
+use your own build instead:
+
+```jsonc
+{
+  "dap": {
+    "netcoredbg": {
+      "binary": "/usr/local/bin/netcoredbg"
+    }
+  }
+}
+```
+
+Create `.zed/debug.json` in your project for explicit configurations:
+
+```jsonc
+[
+  {
+    "label": "Debug console app",
+    "adapter": "netcoredbg",
+    "request": "launch",
+    "program": "$ZED_WORKTREE_ROOT/bin/Debug/net10.0/App.dll",
+    "cwd": "$ZED_WORKTREE_ROOT",
+    "stopAtEntry": false,
+    "justMyCode": true
+  },
+  {
+    "label": "Attach to process",
+    "adapter": "netcoredbg",
+    "request": "attach",
+    "processId": 0
+  }
+]
+```
+
+Starting a debug session from a `dotnet run` task uses the bundled `dotnet`
+locator: it runs the build first, asks MSBuild for the produced assembly with
+`dotnet msbuild -getProperty:TargetPath`, and launches netcoredbg against it.
+
+### Debugging a single test
+
+The locator deliberately does not handle `dotnet test`: the test assembly is a
+library driven by VSTest, and launching it directly exits without running
+anything. Instead, run the **"dotnet test $ZED_SYMBOL (wait for debugger)"**
+task from the gutter button on any test. The test host prints its process id
+and waits; start an `attach` configuration with that id and breakpoints inside
+the test are hit normally.
+
+## Runnables
+
+Test methods (`[Fact]`, `[Theory]`, `[Test]`, `[TestMethod]`, `[TestCase]`),
+test classes (including xUnit classes, which carry no class-level attribute),
+and `Main` methods get a run button in the gutter.
+
 ## Development
 
 To develop this extension, see the [Developing Extensions](https://zed.dev/docs/extensions/developing-extensions) section of the Zed docs.

debug_adapter_schemas/netcoredbg.json

@@ -0,0 +1,81 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "netcoredbg debug configuration",
+  "description": "Debug configuration for .NET applications, handled by netcoredbg.",
+  "oneOf": [
+    {
+      "type": "object",
+      "required": ["request", "program"],
+      "properties": {
+        "request": {
+          "type": "string",
+          "const": "launch",
+          "description": "Start a new .NET process under the debugger."
+        },
+        "program": {
+          "type": "string",
+          "description": "Absolute path to the managed assembly to debug, e.g. bin/Debug/net10.0/App.dll."
+        },
+        "args": {
+          "type": "array",
+          "items": { "type": "string" },
+          "default": [],
+          "description": "Command-line arguments passed to the program."
+        },
+        "cwd": {
+          "type": "string",
+          "description": "Working directory for the debuggee. Defaults to the worktree root."
+        },
+        "env": {
+          "type": "object",
+          "additionalProperties": { "type": "string" },
+          "default": {},
+          "description": "Environment variables set for the debuggee."
+        },
+        "stopAtEntry": {
+          "type": "boolean",
+          "default": false,
+          "description": "Break as soon as the entry point is reached."
+        },
+        "justMyCode": {
+          "type": "boolean",
+          "default": true,
+          "description": "Restrict stepping and breakpoints to code built from this solution."
+        },
+        "enableStepFiltering": {
+          "type": "boolean",
+          "default": true,
+          "description": "Step over property getters, setters, and operators."
+        },
+        "console": {
+          "type": "string",
+          "enum": ["internalConsole", "integratedTerminal", "externalTerminal"],
+          "default": "internalConsole",
+          "description": "Where the debuggee's stdio is attached."
+        }
+      },
+      "additionalProperties": true
+    },
+    {
+      "type": "object",
+      "required": ["request"],
+      "properties": {
+        "request": {
+          "type": "string",
+          "const": "attach",
+          "description": "Attach to an already running .NET process."
+        },
+        "processId": {
+          "type": ["integer", "string"],
+          "description": "Process id to attach to."
+        },
+        "justMyCode": {
+          "type": "boolean",
+          "default": true,
+          "description": "Restrict stepping and breakpoints to code built from this solution."
+        }
+      },
+      "additionalProperties": true
+    }
+  ]
+}

extension.toml

@@ -21,6 +21,31 @@ language = "CSharp"
 name = "csharp-ls"
 language = "CSharp"
 
+[debug_adapters.netcoredbg]
+schema_path = "debug_adapter_schemas/netcoredbg.json"
+
+# Turns a `dotnet run` task into a build-then-debug scenario.
+[debug_locators.dotnet]
+
+# netcoredbg release archives; GitHub asset downloads redirect to
+# objects.githubusercontent.com.
+[[capabilities]]
+kind = "download_file"
+host = "github.com"
+path = ["Samsung", "netcoredbg", "releases", "**"]
+
+[[capabilities]]
+kind = "download_file"
+host = "objects.githubusercontent.com"
+path = ["**"]
+
+# Used by the `dotnet` debug locator to ask MSBuild where the build output
+# landed (`dotnet msbuild -getProperty:TargetPath`).
+[[capabilities]]
+kind = "process:exec"
+command = "dotnet"
+args = ["**"]
+
 [grammars.c_sharp]
 repository = "https://github.com/tree-sitter/tree-sitter-c-sharp"
 commit = "485f0bae0274ac9114797fc10db6f7034e4086e3"

languages/csharp/config.toml

@@ -3,6 +3,7 @@ code_fence_block_name = "csharp"
 grammar = "c_sharp"
 path_suffixes = ["cs"]
 line_comments = ["// ", "/// "]
+debuggers = ["netcoredbg"]
 autoclose_before = ";:.,=}])>"
 brackets = [
     { start = "{", end = "}", close = true, newline = true },

languages/csharp/debugger.scm

@@ -0,0 +1,73 @@
+; Identifiers whose value is worth showing while a debug session is paused.
+;
+; The `#not-match?` guards drop PascalCase identifiers in positions where a
+; type name is as likely as a variable, since evaluating a type produces noise
+; rather than a value.
+
+(parameter
+  name: (identifier) @debug-variable)
+
+(variable_declarator
+  name: (identifier) @debug-variable)
+
+(declaration_expression
+  name: (identifier) @debug-variable)
+
+(catch_declaration
+  name: (identifier) @debug-variable)
+
+(foreach_statement
+  left: (identifier) @debug-variable)
+
+(assignment_expression
+  left: (identifier) @debug-variable)
+
+(assignment_expression
+  left: (member_access_expression) @debug-variable)
+
+(element_access_expression
+  expression: (identifier) @debug-variable)
+
+(member_access_expression
+  expression: (identifier) @debug-variable
+  (#not-match? @debug-variable "^[A-Z]"))
+
+(argument
+  (identifier) @debug-variable
+  (#not-match? @debug-variable "^[A-Z]"))
+
+(binary_expression
+  (identifier) @debug-variable
+  (#not-match? @debug-variable "^[A-Z]"))
+
+(prefix_unary_expression
+  (identifier) @debug-variable)
+
+(postfix_unary_expression
+  (identifier) @debug-variable)
+
+(return_statement
+  (identifier) @debug-variable)
+
+(interpolation
+  (identifier) @debug-variable)
+
+(if_statement
+  condition: (identifier) @debug-variable)
+
+(while_statement
+  condition: (identifier) @debug-variable)
+
+(switch_statement
+  value: (identifier) @debug-variable)
+
+(conditional_expression
+  condition: (identifier) @debug-variable)
+
+(await_expression
+  (identifier) @debug-variable)
+
+[
+  (block)
+  (declaration_list)
+] @debug-scope

languages/csharp/runnables.scm

@@ -0,0 +1,35 @@
+; A test method: xUnit `[Fact]`/`[Theory]`, NUnit `[Test]`, MSTest `[TestMethod]`.
+((method_declaration
+  (attribute_list
+    (attribute
+      name: (identifier) @_attribute))
+  name: (_) @run)
+  (#match? @_attribute "^(Fact|Theory|Test|TestMethod|TestCase)$")
+  (#set! tag csharp-test))
+
+; A test class declared as such: MSTest `[TestClass]`, NUnit `[TestFixture]`.
+((class_declaration
+  (attribute_list
+    (attribute
+      name: (identifier) @_attribute))
+  name: (_) @run)
+  (#match? @_attribute "^(TestClass|TestFixture)$")
+  (#set! tag csharp-test-class))
+
+; A test class recognised by its contents. xUnit marks no class-level
+; attribute, so the only way to spot one is that it holds a test method.
+((class_declaration
+  name: (_) @run
+  body: (declaration_list
+    (method_declaration
+      (attribute_list
+        (attribute
+          name: (identifier) @_attribute)))))
+  (#match? @_attribute "^(Fact|Theory|Test|TestMethod|TestCase)$")
+  (#set! tag csharp-test-class))
+
+; The entry point of an executable project.
+((method_declaration
+  name: (_) @run)
+  (#eq? @run "Main")
+  (#set! tag csharp-main))

languages/csharp/tasks.json

@@ -0,0 +1,25 @@
+[
+  {
+    "label": "dotnet test $ZED_SYMBOL",
+    "command": "dotnet",
+    "args": ["test", "--filter", "FullyQualifiedName~$ZED_SYMBOL"],
+    "cwd": "$ZED_WORKTREE_ROOT",
+    "tags": ["csharp-test", "csharp-test-class"]
+  },
+  {
+    "label": "dotnet test $ZED_SYMBOL (wait for debugger)",
+    "command": "dotnet",
+    "args": ["test", "--filter", "FullyQualifiedName~$ZED_SYMBOL"],
+    "env": { "VSTEST_HOST_DEBUG": "1" },
+    "cwd": "$ZED_WORKTREE_ROOT",
+    "reveal": "always",
+    "tags": ["csharp-test", "csharp-test-class"]
+  },
+  {
+    "label": "dotnet run",
+    "command": "dotnet",
+    "args": ["run"],
+    "cwd": "$ZED_DIRNAME",
+    "tags": ["csharp-main"]
+  }
+]