Incremental typechecking (#939)

* basic PoC of doing a sort of incremental typechecking

* move incremental compilation stuff to its own file

* reset back version

* more work

* refactor

* fixes and adjustments for namespaced packages

* adjust watching

* make incremental compilation of resi work

* report error when incremental typechecking fails

* config tweaks

* more guard rails

* debug logging switch

* robustness

* changelog

Author: zth

.vscode/launch.json

@@ -11,7 +11,7 @@
 				"--extensionDevelopmentPath=${workspaceRoot}"
 			],
 			"outFiles": [
-				"${workspaceRoot}/client/out/*.js"
+				"${workspaceRoot}/client/out/**/*.js"
 			],
 			"preLaunchTask": {
 				"type": "npm",
@@ -25,7 +25,7 @@
 			"port": 6009,
 			"restart": true,
 			"outFiles": [
-				"${workspaceRoot}/server/out/*.js"
+				"${workspaceRoot}/server/out/**/*.js"
 			]
 		},
 		{

.vscodeignore

@@ -18,4 +18,5 @@ tools.opam
 client/node_modules
 server/node_modules
 _opam
-_build
+_build
+Makefile

CHANGELOG.md

@@ -12,14 +12,15 @@
 
 ## master
 
-## 1.42.0
+#### :rocket: New Feature
 
-#### :bug: Bug Fix
+- Experimental support for type checking without saving the file :tada:. https://github.com/rescript-lang/rescript-vscode/pull/939
 
-- Fix issue with unlabelled arg code swallowing completions. https://github.com/rescript-lang/rescript-vscode/pull/937
+## 1.42.0
 
 #### :bug: Bug Fix
 
+- Fix issue with unlabelled arg code swallowing completions. https://github.com/rescript-lang/rescript-vscode/pull/937
 - Fix issue where completion inside of switch expression would not work in some cases. https://github.com/rescript-lang/rescript-vscode/pull/936
 - Fix bug that made empty prop expressions in JSX not complete if in the middle of a JSX element. https://github.com/rescript-lang/rescript-vscode/pull/935
 

analysis/src/Cmt.ml

@@ -16,13 +16,25 @@ let fullFromUri ~uri =
     let moduleName =
       BuildSystem.namespacedName package.namespace (FindFiles.getName path)
     in
-    match Hashtbl.find_opt package.pathsForModule moduleName with
-    | Some paths ->
-      let cmt = getCmtPath ~uri paths in
-      fullForCmt ~moduleName ~package ~uri cmt
-    | None ->
-      prerr_endline ("can't find module " ^ moduleName);
-      None)
+    let incrementalCmtPath =
+      package.rootPath ^ "/lib/bs/___incremental" ^ "/" ^ moduleName
+      ^
+      match Files.classifySourceFile path with
+      | Resi -> ".cmti"
+      | _ -> ".cmt"
+    in
+    match fullForCmt ~moduleName ~package ~uri incrementalCmtPath with
+    | Some cmtInfo ->
+      if Debug.verbose () then Printf.printf "[cmt] Found incremental cmt\n";
+      Some cmtInfo
+    | None -> (
+      match Hashtbl.find_opt package.pathsForModule moduleName with
+      | Some paths ->
+        let cmt = getCmtPath ~uri paths in
+        fullForCmt ~moduleName ~package ~uri cmt
+      | None ->
+        prerr_endline ("can't find module " ^ moduleName);
+        None))
 
 let fullsFromModule ~package ~moduleName =
   if Hashtbl.mem package.pathsForModule moduleName then

package.json

@@ -176,6 +176,21 @@
 					"default": true,
 					"description": "Enable signature help for function calls."
 				},
+				"rescript.settings.incrementalTypechecking.enabled": {
+					"type": "boolean",
+					"default": false,
+					"description": "(beta/experimental) Enable incremental type checking."
+				},
+				"rescript.settings.incrementalTypechecking.acrossFiles": {
+					"type": "boolean",
+					"default": false,
+					"description": "(beta/experimental) Enable incremental type checking across files, so that unsaved file A gets access to unsaved file B."
+				},
+				"rescript.settings.incrementalTypechecking.debugLogging": {
+					"type": "boolean",
+					"default": false,
+					"description": "(debug) Enable debug logging (ends up in the extension output)."
+				},
 				"rescript.settings.binaryPath": {
 					"type": [
 						"string",
@@ -230,9 +245,9 @@
 	},
 	"scripts": {
 		"clean": "rm -rf client/out server/out",
-		"vscode:prepublish": "npm run clean && npm run compile && npm run bundle",
-		"compile": "tsc",
-		"watch": "tsc -w",
+		"vscode:prepublish": "npm run clean && npm run bundle",
+		"compile": "tsc -b",
+		"watch": "tsc -b -w",
 		"postinstall": "cd server && npm i && cd ../client && npm i && cd ../tools && npm i && cd ../tools/tests && npm i && cd ../../analysis/tests && npm i && cd ../reanalyze/examples/deadcode && npm i && cd ../termination && npm i",
 		"bundle-server": "esbuild server/src/cli.ts --bundle --sourcemap --outfile=server/out/cli.js --format=cjs --platform=node --loader:.node=file --minify",
 		"bundle-client": "esbuild client/src/extension.ts --bundle --external:vscode --sourcemap --outfile=client/out/extension.js --format=cjs --platform=node --loader:.node=file --minify",

server/src/config.ts

@@ -0,0 +1,49 @@
+import { Message } from "vscode-languageserver-protocol";
+
+export type send = (msg: Message) => void;
+
+export interface extensionConfiguration {
+  allowBuiltInFormatter: boolean;
+  askToStartBuild: boolean;
+  inlayHints: {
+    enable: boolean;
+    maxLength: number | null;
+  };
+  codeLens: boolean;
+  binaryPath: string | null;
+  platformPath: string | null;
+  signatureHelp: {
+    enabled: boolean;
+  };
+  incrementalTypechecking: {
+    enabled: boolean;
+    acrossFiles: boolean;
+    debugLogging: boolean;
+  };
+}
+
+// All values here are temporary, and will be overridden as the server is
+// initialized, and the current config is received from the client.
+let config: { extensionConfiguration: extensionConfiguration } = {
+  extensionConfiguration: {
+    allowBuiltInFormatter: false,
+    askToStartBuild: true,
+    inlayHints: {
+      enable: false,
+      maxLength: 25,
+    },
+    codeLens: false,
+    binaryPath: null,
+    platformPath: null,
+    signatureHelp: {
+      enabled: true,
+    },
+    incrementalTypechecking: {
+      enabled: false,
+      acrossFiles: true,
+      debugLogging: true,
+    },
+  },
+};
+
+export default config;