Fix format diagnostics on old TypeScript versions

Author: blakeembrey

src/index.spec.ts

@@ -370,41 +370,43 @@ describe('ts-node', function () {
       expect(() => require(moduleTestPath)).to.not.throw()
     })
 
-    it('should support compiler scopes', function () {
-      const calls: string[] = []
+    if (semver.gte(ts.version, '2.7.0')) {
+      it('should support compiler scopes', function () {
+        const calls: string[] = []
 
-      registered.enabled(false)
+        registered.enabled(false)
 
-      const compilers = [
-        register({ cwd: join(TEST_DIR, 'scope/a'), scope: true }),
-        register({ cwd: join(TEST_DIR, 'scope/b'), scope: true })
-      ]
+        const compilers = [
+          register({ cwd: join(TEST_DIR, 'scope/a'), scope: true }),
+          register({ cwd: join(TEST_DIR, 'scope/b'), scope: true })
+        ]
 
-      compilers.forEach(c => {
-        const old = c.compile
-        c.compile = (code, fileName, lineOffset) => {
-          calls.push(fileName)
+        compilers.forEach(c => {
+          const old = c.compile
+          c.compile = (code, fileName, lineOffset) => {
+            calls.push(fileName)
 
-          return old(code, fileName, lineOffset)
-        }
-      })
+            return old(code, fileName, lineOffset)
+          }
+        })
 
-      try {
-        expect(require('../tests/scope/a').ext).to.equal('.ts')
-        expect(require('../tests/scope/b').ext).to.equal('.ts')
-      } finally {
-        compilers.forEach(c => c.enabled(false))
-      }
+        try {
+          expect(require('../tests/scope/a').ext).to.equal('.ts')
+          expect(require('../tests/scope/b').ext).to.equal('.ts')
+        } finally {
+          compilers.forEach(c => c.enabled(false))
+        }
 
-      expect(calls).to.deep.equal([
-        join(TEST_DIR, 'scope/a/index.ts'),
-        join(TEST_DIR, 'scope/b/index.ts')
-      ])
+        expect(calls).to.deep.equal([
+          join(TEST_DIR, 'scope/a/index.ts'),
+          join(TEST_DIR, 'scope/b/index.ts')
+        ])
 
-      delete require.cache[moduleTestPath]
+        delete require.cache[moduleTestPath]
 
-      expect(() => require(moduleTestPath)).to.throw()
-    })
+        expect(() => require(moduleTestPath)).to.throw()
+      })
+    }
 
     it('should compile through js and ts', function () {
       const m = require('../tests/complex')

src/index.ts

@@ -268,7 +268,7 @@ export function register (opts: Options = {}): Register {
   })
 
   const formatDiagnostics = process.stdout.isTTY || options.pretty
-    ? ts.formatDiagnosticsWithColorAndContext
+    ? (ts.formatDiagnosticsWithColorAndContext || ts.formatDiagnostics)
     : ts.formatDiagnostics
 
   function createTSError (diagnostics: ReadonlyArray<_ts.Diagnostic>) {