Slow compilation time for a hello world program (7/8 seconds)

TypeScript Version: 3.9.5

Issue: I created a simple hello world program, and it took 3s to compile with --skipLibCheck, and 7/8s without. is there a way to improve compile time? output of my terminal:

➜  cat hello.ts
console.log('hello world');
➜  time tsc --skipLibCheck --extendedDiagnostics hello.ts
Files:                         77
Lines:                      42747
Nodes:                     186757
Identifiers:                67158
Symbols:                    44908
Types:                         80
Instantiations:                 0
Memory used:               69869K
Assignability cache size:       0
Identity cache size:            0
Subtype cache size:             0
Strict subtype cache size:      0
I/O Read time:              0.01s
Parse time:                 0.85s
ResolveTypeReference time:  0.01s
ResolveModule time:         0.04s
Program time:               0.96s
Bind time:                  0.56s
Check time:                 0.01s
transformTime time:         0.01s
commentTime time:           0.00s
I/O Write time:             0.00s
printTime time:             0.02s
Emit time:                  0.02s
Total time:                 1.56s
tsc --skipLibCheck --extendedDiagnostics hello.ts  3.45s user 0.09s system 187% cpu 1.889 total

Additional info: OS: Windows 10 Intel Core i7-8565U CPU @ 1.80GHZ / 16GB RAM / SSD SATA Terminal: WSL 2 (ubuntu) Node version: v14.4.0

Expected behavior: 0.1s compilation.

Actual behavior: 3/4s second compilation, without skipLibCheck it goes to 7/8s.

Notes:

• when I compile this program with deno (deno run hello.ts), it takes 0.5s, which is good! is there a way to have something close to deno with tsc? maybe by using a v8 snapshot as they did?

Related Issues:

• https://github.com/microsoft/TypeScript/issues/36396 – reason was slow CPU. but mine seems to be better.

Search Terms:

• slow compilation
• improve startup time
• v8 snapshot

[DanielRosenwasser]

Here’s the new section: Controlling @types Inclusion.

[DanielRosenwasser]

You can set the "types" field to [] which should stop TypeScript from automatically sucking in all @types/ folders unless you import them. I’ll update the Performance page to mention this too.