package.json

@@ -1,6 +1,6 @@
 {
   "name": "ts-node",
-  "version": "8.8.1",
+  "version": "8.8.2",
   "description": "TypeScript execution environment and REPL for node.js, with source map support",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/index.spec.ts

@@ -340,12 +340,36 @@ describe('ts-node', function () {
       })
     })
 
-    it('issue #884', function (done) {
-      exec(`node "${BIN_PATH}" --project tests/issue-884/tsconfig.json tests/issue-884`, function (err, stdout) {
-        expect(err).to.equal(null)
-        expect(stdout).to.equal('')
+    describe('issue #884', function () {
+      it('should compile', function (done) {
+        exec(`node "${BIN_PATH}" --project tests/issue-884/tsconfig.json tests/issue-884`, function (err, stdout) {
+          expect(err).to.equal(null)
+          expect(stdout).to.equal('')
 
-        return done()
+          return done()
+        })
+      })
+    })
+
+    describe('issue #986', function () {
+      it('should not compile', function (done) {
+        exec(`node "${BIN_PATH}" --project tests/issue-986/tsconfig.json tests/issue-986`, function (err, stdout, stderr) {
+          expect(err).not.to.equal(null)
+          expect(stderr).to.contain('Cannot find name \'TEST\'') // TypeScript error.
+          expect(stdout).to.equal('')
+
+          return done()
+        })
+      })
+
+      it('should compile with `--files`', function (done) {
+        exec(`node "${BIN_PATH}" --files --project tests/issue-986/tsconfig.json tests/issue-986`, function (err, stdout, stderr) {
+          expect(err).not.to.equal(null)
+          expect(stderr).to.contain('ReferenceError: TEST is not defined') // Runtime error.
+          expect(stdout).to.equal('')
+
+          return done()
+        })
       })
     })
 

src/index.ts

@@ -507,17 +507,16 @@ export function create (rawOptions: CreateOptions = {}): Register {
       const service = ts.createLanguageService(serviceHost, registry)
 
       const updateMemoryCache = (contents: string, fileName: string) => {
-        const fileVersion = fileVersions.get(fileName) || 0
-
         // Add to `rootFiles` when discovered for the first time.
-        if (fileVersion === 0) {
+        if (!fileVersions.has(fileName)) {
           rootFileNames.push(fileName)
         }
 
+        const previousVersion = fileVersions.get(fileName) || 0
         const previousContents = fileContents.get(fileName)
         // Avoid incrementing cache when nothing has changed.
         if (contents !== previousContents) {
-          fileVersions.set(fileName, fileVersion + 1)
+          fileVersions.set(fileName, previousVersion + 1)
           fileContents.set(fileName, contents)
           // Increment project version for every file change.
           projectVersion++

tests/issue-986/index.ts

@@ -0,0 +1 @@
+console.log(TEST)

tests/issue-986/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "module": "CommonJS"
+  }
+}

tests/issue-986/types.ts

@@ -0,0 +1 @@
+declare const TEST: string