Add formatter implementation into the extension

.gitignore

@@ -1,6 +1,7 @@
 # client executables files
 node_modules/
 out/
+.idea/
 
 .pnpm-debug.log
 

.vscodeignore

@@ -11,3 +11,4 @@ package-lock.json
 eslint.config.ts
 *.ts
 dist/**/*.map
+assets

README.md

@@ -1,24 +1,29 @@
 # SimplicityHL extension for VSCode
 
-VSCode extension that provides syntax highlighting for the [SimplicityHL](https://github.com/BlockstreamResearch/SimplicityHL) programming language.
+VSCode extension that provides syntax highlighting for the [SimplicityHL][1] programming language.
 
-[Simplicity](https://github.com/BlockstreamResearch/simplicity) is a typed, combinator-based, functional language without loops or recursion, developed to be an alternative to Bitcoin script that is formally specified, and can be statically analyzed with upper bounds on computation resources prior to execution.
+[Simplicity][2] is a typed, combinator-based, functional language without loops or recursion, developed to be an alternative to Bitcoin script that is formally specified, and can be statically analyzed with upper bounds on computation resources prior to execution.
 
-SimplicityHL is a high-level language for writing Simplicity smart contracts. SimplicityHL looks and feels like [Rust](https://www.rust-lang.org), but is compiled to Simplicity bytecode. Developers write SimplicityHL transactions, which Bitcoin/Liquid nodes verify with the Simplicity script interpreter.
+SimplicityHL is a high-level language for writing Simplicity smart contracts. SimplicityHL looks and feels like [Rust][3], but is compiled to Simplicity bytecode. Developers write SimplicityHL transactions, which Bitcoin/Liquid nodes verify with the Simplicity script interpreter.
 
 ## Features
 
 - Syntax highlighting and snippets for `.simf` and `.wit` files
 - Compiler diagnostics, completion, hover, signature help, symbols, references, and go to definition
 - Opt-in imports and enums support in the language server and direct compiler commands
+- Formatting of SimplicityHL code using default VSCode bindings
 
-The extension installs or connects to the [SimplicityHL language server](https://github.com/BlockstreamResearch/simplicityhl-lsp), which provides language intelligence:
+The extension installs or connects to the [SimplicityHL language server][4], which provides language intelligence. 
+To provide concise and clear code you can also use the [simfmt][5] formatter.
 
 - Error diagnostics
-![diagnostics](https://github.com/user-attachments/assets/54315645-464b-40c3-bb72-c6e8c4bc0ad5)
+![diagnostics][6]
 
 - Completion of user-defined functions, imported items, built-ins, and jets
-![completion](https://github.com/user-attachments/assets/bbc2b9de-c286-4d31-b47e-ac95885f8916)
+![completion][7]
+
+- Formatting of SimplicityHL code
+![formatting][8]
 
 ## Experimental features
 
@@ -34,4 +39,14 @@ For local extension development, `simplicityhl.server.path` can point to a local
 
 ### Development
 
-To install the extension manually or hack on the source code see [development.md](docs/development.md)
+To install the extension manually or hack on the source code see [development.md][9]
+
+[1]: https://github.com/BlockstreamResearch/SimplicityHL
+[2]: https://github.com/BlockstreamResearch/simplicity
+[3]: https://www.rust-lang.org
+[4]: https://github.com/BlockstreamResearch/simplicityhl-lsp
+[5]: https://github.com/BlockstreamResearch/simfmt
+[6]: https://raw.githubusercontent.com/BlockstreamResearch/simplicityhl-vscode/master/assets/error_diagnostic.gif
+[7]: https://raw.githubusercontent.com/BlockstreamResearch/simplicityhl-vscode/master/assets/completion.gif
+[8]: https://raw.githubusercontent.com/BlockstreamResearch/simplicityhl-vscode/master/assets/formatting.gif
+[9]: https://raw.githubusercontent.com/BlockstreamResearch/simplicityhl-vscode/master/docs/development.md

package.json

@@ -2,7 +2,7 @@
   "name": "simplicityhl",
   "displayName": "SimplicityHL Language Support",
   "description": "Syntax highlighting and autocompletion for SimplicityHL (Simfony) language",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "publisher": "Blockstream",
   "repository": {
     "type": "git",
@@ -95,6 +95,22 @@
             "default": "",
             "description": "Path to the simc compiler. If empty, searches PATH and common locations."
           },
+          "simplicityhl.formatter.path": {
+            "type": "string",
+            "default": "",
+            "scope": "machine-overridable",
+            "description": "Path to the simfmt formatter. If empty, searches PATH and common locations."
+          },
+          "simplicityhl.formatter.autoSaveBeforeFormat": {
+            "type": "boolean",
+            "default": true,
+            "description": "Automatically save the file before formatting."
+          },
+          "simplicityhl.formatter.disableAutoupdate": {
+            "type": "boolean",
+            "default": false,
+            "description": "Do not autoupdate simfmt formatter."
+          },
           "simplicityhl.build.autoSaveBeforeCompile": {
             "type": "boolean",
             "default": true,
@@ -118,6 +134,11 @@
         }
       }
     ],
+    "configurationDefaults": {
+      "[simplicityhl]": {
+        "editor.defaultFormatter": "Blockstream.simplicityhl"
+      }
+    },
     "commands": [
       {
         "command": "simplicityhl.restartServer",
@@ -144,6 +165,11 @@
         "command": "simplicityhl.compileJson",
         "title": "Compile to JSON",
         "category": "SimplicityHL"
+      },
+      {
+        "command": "simplicityhl.formatFile",
+        "title": "Format Current File",
+        "category": "SimplicityHL"
       }
     ],
     "menus": {
@@ -164,6 +190,11 @@
           "when": "resourceLangId == simplicityhl",
           "command": "simplicityhl.compileWithWitness",
           "group": "1_modification"
+        },
+        {
+          "when": "resourceLangId == simplicityhl",
+          "command": "simplicityhl.formatFile",
+          "group": "1_modification"
         }
       ],
       "commandPalette": [
@@ -182,6 +213,10 @@
         {
           "command": "simplicityhl.compileJson",
           "when": "resourceLangId == simplicityhl"
+        },
+        {
+          "command": "simplicityhl.formatFile",
+          "when": "resourceLangId == simplicityhl"
         }
       ]
     },
@@ -240,7 +275,7 @@
     "compile": "npm run check-types && node esbuild.mjs --production",
     "check": "npm test && npm run eslint-check && npm run compile",
     "check-types": "tsc --noEmit",
-    "test": "node --test -r ts-node/register src/contracts.test.ts src/find_executable.test.ts",
+    "test": "node --test -r ts-node/register src/contracts.test.ts src/find_executable.test.ts src/update_cache.test.ts src/find_server.test.ts src/format/output.test.ts",
     "watch": "npm-run-all -p watch:*",
     "watch:esbuild": "node esbuild.mjs --watch",
     "watch:tsc": "tsc --noEmit --watch --project tsconfig.json",

src/commands/compile.ts

@@ -8,47 +8,28 @@ import type { CompileOptions } from "../compiler/args";
 import {
   COMMAND_IDS,
   CONFIGURATION_SECTION,
-  LANGUAGE_IDS,
   SETTINGS,
 } from "../contracts";
+import { getActiveSimplicityHLDocument } from "../document";
 
 function showCompilationFailed(): void {
   vscode.window.showErrorMessage(
     "Compilation failed. See the SimplicityHL Compiler output for details."
   );
 }
 
-// Validates that the active editor contains a SimplicityHL file
+// Gets the active SimplicityHL file and auto-saves it when configured.
 async function getSimplicityHLDocument(): Promise<vscode.TextDocument | undefined> {
-  const editor = vscode.window.activeTextEditor;
-  if (!editor) {
-    vscode.window.showWarningMessage("No active file to compile");
-    return undefined;
-  }
-
-  const document = editor.document;
-  if (document.languageId !== LANGUAGE_IDS.source) {
-    vscode.window.showWarningMessage("Current file is not a SimplicityHL file (.simf)");
-    return undefined;
-  }
-
-  // Auto-save before compile if enabled
   const config = vscode.workspace.getConfiguration(CONFIGURATION_SECTION);
   const autoSave = config.get<boolean>(
     SETTINGS.autoSaveBeforeCompile.key,
     SETTINGS.autoSaveBeforeCompile.default,
   );
-  if (autoSave && document.isDirty) {
-    const saved = await document.save();
-    if (!saved) {
-      void vscode.window.showWarningMessage(
-        "SimplicityHL compilation canceled because the file could not be saved.",
-      );
-      return undefined;
-    }
-  }
-
-  return document;
+  return getActiveSimplicityHLDocument({
+    action: "compile",
+    saveBeforeAction: autoSave,
+    failIfSaveFails: true,
+  });
 }
 
 async function compileActiveDocument(

src/commands/format.ts

@@ -0,0 +1,33 @@
+// Command and native provider registration for SimplicityHL formatting.
+
+import * as vscode from "vscode";
+import { COMMAND_IDS, LANGUAGE_IDS } from "../contracts";
+import { getActiveSimplicityHLDocument } from "../document";
+import type { SimplicityHLFormatter } from "../format";
+
+export function registerFormattingCommands(
+  context: vscode.ExtensionContext,
+  formatter: () => SimplicityHLFormatter,
+): void {
+  const formatFileCommand = vscode.commands.registerCommand(
+    COMMAND_IDS.formatFile,
+    async () => {
+      const document = await getActiveSimplicityHLDocument({ action: "format" });
+      if (!document) return;
+
+      await formatter().formatDocument(document);
+    },
+  );
+
+  const provider = vscode.languages.registerDocumentFormattingEditProvider(
+    { language: LANGUAGE_IDS.source },
+    {
+      provideDocumentFormattingEdits(document, options, token) {
+        if (token.isCancellationRequested) return undefined;
+        return formatter().provideDocumentFormattingEdits(document, options, token);
+      },
+    },
+  );
+
+  context.subscriptions.push(formatFileCommand, provider);
+}

src/contracts.test.ts

@@ -3,7 +3,7 @@ import * as fs from "node:fs";
 import * as path from "node:path";
 import { test } from "node:test";
 
-import { SETTINGS, languageClientOptions } from "./contracts";
+import { COMMAND_IDS, SETTINGS, languageClientOptions } from "./contracts";
 
 void test("client languages and consumed settings match package contributions", () => {
   const manifest = JSON.parse(
@@ -24,12 +24,23 @@ void test("client languages and consumed settings match package contributions",
     ),
   ) as Record<string, { default?: unknown }>;
 
-  for (const setting of [SETTINGS.serverPath, SETTINGS.imports, SETTINGS.enums]) {
+  for (const setting of [
+    SETTINGS.serverPath,
+    SETTINGS.imports,
+    SETTINGS.enums,
+    SETTINGS.formatterPath,
+    SETTINGS.autoSaveBeforeFormat,
+    SETTINGS.formatterDisableAutoupdate,
+  ]) {
     const contribution =
       contributedSettings[
         `${clientOptions.synchronize.configurationSection}.${setting.key}`
       ];
     assert.ok(contribution, `Missing package contribution for ${setting.key}`);
     assert.equal(contribution.default, setting.default);
   }
+
+  assert.ok(contributions.commands.some(
+    ({ command }: { command: string }) => command === COMMAND_IDS.formatFile,
+  ));
 });

src/contracts.ts

@@ -2,6 +2,8 @@ export const CONFIGURATION_SECTION = "simplicityhl";
 export const LANGUAGE_CLIENT_ID = "simplicityhlLspClient";
 export const LANGUAGE_CLIENT_NAME = "SimplicityHL LSP";
 export const SERVER_BINARY = "simplicityhl-lsp";
+export const FORMATTER_BINARY = "simfmt";
+export const FORMATTER_UPDATE_CACHE_KEY = "simfmt.lastUpdateAttemptAt";
 export const TASK_TYPE = "simplicityhl";
 
 export const LANGUAGE_IDS = {
@@ -15,6 +17,7 @@ export const COMMAND_IDS = {
   compileFileDebug: "simplicityhl.compileFileDebug",
   compileWithWitness: "simplicityhl.compileWithWitness",
   compileJson: "simplicityhl.compileJson",
+  formatFile: "simplicityhl.formatFile",
 } as const;
 
 export const TASK_COMMANDS = [
@@ -40,6 +43,18 @@ export const SETTINGS = {
     key: "compiler.path",
     default: "",
   },
+  formatterPath: {
+    key: "formatter.path",
+    default: "",
+  },
+  autoSaveBeforeFormat: {
+    key: "formatter.autoSaveBeforeFormat",
+    default: true,
+  },
+  formatterDisableAutoupdate: {
+    key: "formatter.disableAutoupdate",
+    default: false,
+  },
   autoSaveBeforeCompile: {
     key: "build.autoSaveBeforeCompile",
     default: true,