Adds VFS deleteFile method (#3173)

Co-authored-by: Jake Bailey <5341706+jakebailey@users.noreply.github.com>

Author: marklundin

.changeset/tame-garlics-shop.md

@@ -0,0 +1,5 @@
+---
+"@typescript/vfs": minor
+---
+
+Adds `deleteFile` to the vfs api to which allows file to be removed from the file system.

packages/typescript-vfs/src/index.ts

@@ -32,6 +32,7 @@ export interface VirtualTypeScriptEnvironment {
   getSourceFile: (fileName: string) => import("typescript").SourceFile | undefined
   createFile: (fileName: string, content: string) => void
   updateFile: (fileName: string, content: string, replaceTextSpan?: import("typescript").TextSpan) => void
+  deleteFile: (fileName: string) => void
 }
 
 /**
@@ -54,7 +55,7 @@ export function createVirtualTypeScriptEnvironment(
 ): VirtualTypeScriptEnvironment {
   const mergedCompilerOpts = { ...defaultCompilerOptions(ts), ...compilerOptions }
 
-  const { languageServiceHost, updateFile } = createVirtualLanguageServiceHost(
+  const { languageServiceHost, updateFile, deleteFile } = createVirtualLanguageServiceHost(
     sys,
     rootFiles,
     mergedCompilerOpts,
@@ -99,6 +100,12 @@ export function createVirtualTypeScriptEnvironment(
 
       updateFile(newSourceFile)
     },
+    deleteFile(fileName) {
+      const sourceFile = languageService.getProgram()!.getSourceFile(fileName)
+      if (sourceFile) {
+        deleteFile(sourceFile)
+      }
+    }
   }
 }
 
@@ -466,6 +473,9 @@ export function createSystem(files: Map<string, string>): System {
     writeFile: (fileName, contents) => {
       files.set(fileName, contents)
     },
+    deleteFile: (fileName) => {
+      files.delete(fileName)
+    },
   }
 }
 
@@ -545,6 +555,9 @@ export function createFSBackedSystem(
     writeFile: (fileName, contents) => {
       files.set(fileName, contents)
     },
+    deleteFile: (fileName) => {
+      files.delete(fileName)
+    },
     realpath: nodeSys.realpath,
   }
 }
@@ -564,6 +577,7 @@ export function createVirtualCompilerHost(sys: System, compilerOptions: Compiler
   type Return = {
     compilerHost: CompilerHost
     updateFile: (sourceFile: SourceFile) => boolean
+    deleteFile: (sourceFile: SourceFile) => boolean
   }
 
   const vHost: Return = {
@@ -594,6 +608,12 @@ export function createVirtualCompilerHost(sys: System, compilerOptions: Compiler
       sourceFiles.set(sourceFile.fileName, sourceFile)
       return alreadyExists
     },
+    deleteFile: sourceFile => {
+      const alreadyExists = sourceFiles.has(sourceFile.fileName)
+      sourceFiles.delete(sourceFile.fileName)
+      sys.deleteFile!(sourceFile.fileName)
+      return alreadyExists
+    }
   }
   return vHost
 }
@@ -609,7 +629,7 @@ export function createVirtualLanguageServiceHost(
   customTransformers?: CustomTransformers
 ) {
   const fileNames = [...rootFiles]
-  const { compilerHost, updateFile } = createVirtualCompilerHost(sys, compilerOptions, ts)
+  const { compilerHost, updateFile, deleteFile } = createVirtualCompilerHost(sys, compilerOptions, ts)
   const fileVersions = new Map<string, string>()
   let projectVersion = 0
   const languageServiceHost: LanguageServiceHost = {
@@ -642,6 +662,7 @@ export function createVirtualLanguageServiceHost(
   type Return = {
     languageServiceHost: LanguageServiceHost
     updateFile: (sourceFile: import("typescript").SourceFile) => void
+    deleteFile: (sourceFile: import("typescript").SourceFile) => void
   }
 
   const lsHost: Return = {
@@ -654,6 +675,15 @@ export function createVirtualLanguageServiceHost(
       }
       updateFile(sourceFile)
     },
+    deleteFile: sourceFile => {
+      projectVersion++
+      fileVersions.set(sourceFile.fileName, projectVersion.toString())
+      const index = fileNames.indexOf(sourceFile.fileName)
+      if (index !== -1) {
+        fileNames.splice(index, 1)
+      }
+      deleteFile(sourceFile)
+    }
   }
   return lsHost
 }

packages/typescript-vfs/test/fsbacked.test.ts

@@ -72,3 +72,27 @@ it("searches node_modules/@types", () => {
   const semDiags = env.languageService.getSemanticDiagnostics("index.ts")
   expect(semDiags.length).toBe(0)
 })
+
+it("can delete files in the virtual fs", () => {
+  const compilerOpts: ts.CompilerOptions = { target: ts.ScriptTarget.ES2016, esModuleInterop: true }
+  const fsMap = new Map<string, string>()
+
+  const monorepoRoot = path.join(__dirname, "..", "..", "..")
+  const fakeFolder = path.join(monorepoRoot, "fake")
+  const exporter = path.join(fakeFolder, "file-with-export.ts")
+  const index = path.join(fakeFolder, "index.ts")
+
+  // TODO: the VFS should really be normalizing paths when looking into fsMap instead.
+  fsMap.set(exporter.replace(/\\/g, "/"), `export const helloWorld = "Example string";`)
+  fsMap.set(index.replace(/\\/g, "/"), `import {helloWorld} from "./file-with-export"; console.log(helloWorld)`)
+
+  const system = createFSBackedSystem(fsMap, monorepoRoot, ts)
+  const env = createVirtualTypeScriptEnvironment(system, [index, exporter], ts, compilerOpts)
+  
+  expect(env.getSourceFile(index)).toBeTruthy()
+
+  env.deleteFile(index);
+
+  expect(env.getSourceFile(index)).toBeFalsy()
+
+})