Merge pull request #6 from lydell/local-installs

Support local installs of elm and elm-format
elm-land · Jul 24, 2023 · a5dc4a6 · a5dc4a6
2 parents e2d2e19 + 91501a4
commit a5dc4a6
Show file tree

Hide file tree

Showing 3 changed files with 50 additions and 4 deletions.
diff --git a/src/features/elm-format-on-save.ts b/src/features/elm-format-on-save.ts
@@ -1,7 +1,7 @@
 import * as vscode from "vscode"
 import * as os from "os"
 import * as child_process from "child_process"
-import { Feature } from "./shared/logic"
+import sharedLogic, { Feature } from "./shared/logic"
 
 export const feature: Feature = ({ context }) => {
   context.subscriptions.push(
@@ -38,7 +38,12 @@ function runElmFormat(document: vscode.TextDocument): Promise<string> {
   const command = `elm-format --stdin --yes`
   const original = document.getText()
   return new Promise((resolve, reject) => {
-    const process_ = child_process.exec(command, async (err, stdout, stderr) => {
+    const process_ = child_process.exec(
+      command,
+      {
+        env: sharedLogic.npxEnv()
+      },
+      async (err, stdout, stderr) => {
       if (err) {
         const ELM_FORMAT_BINARY_NOT_FOUND = 127
         if (err.code === ELM_FORMAT_BINARY_NOT_FOUND || err.message.includes(`'elm-format' is not recognized`)) {

diff --git a/src/features/error-highlighting.ts b/src/features/error-highlighting.ts
@@ -128,7 +128,12 @@ const Elm = {
     const command = `(cd ${input.elmJsonFile.projectFolder} && elm make ${deduplicated.join(' ')} --output=/dev/null --report=json)`
     const promise: Promise<ParsedError | undefined> =
       new Promise((resolve) =>
-        child_process.exec(command, async (err, _, stderr) => {
+        child_process.exec(
+          command,
+          {
+            env: sharedLogic.npxEnv()
+          },
+          async (err, _, stderr) => {
           if (err) {
             const ELM_BINARY_NOT_FOUND = 127
             if (err.code === ELM_BINARY_NOT_FOUND || err.message.includes(`'elm' is not recognized`)) {

diff --git a/src/features/shared/logic.ts b/src/features/shared/logic.ts
@@ -1,3 +1,4 @@
+import * as path from 'path'
 import * as vscode from 'vscode'
 import * as AutodetectElmJson from './autodetect-elm-json'
 import { ElmJsonFile, getDocumentationForElmPackage } from './elm-json-file'
@@ -99,6 +100,40 @@ const verifyFileExists = async (fsPath: string): Promise<string | undefined> =>
   }
 }
 
+// Some people install elm and elm-format locally instead of globally, using
+// npm or the elm-tooling CLI. To run locally installed tools, they use `npx`.
+//
+// `npx` adds all potential `node_modules/.bin` up the current directory to the
+// beginning of PATH, for example:
+//
+//     ❯ npx node -p 'process.env.PATH.split(path.delimiter)'
+//     [
+//       '/Users/you/stuff/node_modules/.bin',
+//       '/Users/you/node_modules/.bin',
+//       '/Users/node_modules/.bin',
+//       '/node_modules/.bin',
+//       '/usr/bin',
+//       'etc'
+//     ]
+//
+// This function also does that, so that local installations just work.
+function npxEnv() {
+  return {
+    ...process.env,
+    PATH: [
+      ...(vscode.workspace.workspaceFolders ?? [])
+        .flatMap(folder =>
+          folder.uri.fsPath.split(path.sep)
+            .map((_, index, parts) =>
+              [...parts.slice(0, index + 1), 'node_modules', '.bin'].join(path.sep)
+            )
+            .reverse()
+        ),
+      process.env.PATH
+    ].join(path.delimiter)
+  }
+}
+
 export default {
   pluginId: 'elmLand',
   findElmJsonFor,
@@ -107,5 +142,6 @@ export default {
   findFirstOccurenceOfWordInFile: findFirstOccurrenceOfWordInFile,
   isDefined,
   doesModuleExposesValue,
-  keepFilesThatExist
+  keepFilesThatExist,
+  npxEnv
 }