Very slow incremental compilation in watch mode vs TSServer runtime check

[hippich]

TypeScript Version: 2.x

Code

{
  "description": "This tsconfig file is used to build the main application",
  "compilerOptions": {
    "target": "es5",
    "module": "amd",
    "baseUrl": ".",
    "paths": {
      "*": ["app/*", "app/vendor/*", "app/components/*"]
    },
    "declaration": false,
    "removeComments": false,
    "noLib": false,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "sourceMap": true,
    "pretty": true,
    "allowUnreachableCode": false,
    "allowUnusedLabels": false,
    "noImplicitAny": true,
    "noImplicitReturns": false,
    "noImplicitUseStrict": false,
    "noFallthroughCasesInSwitch": true,
    "moduleResolution": "node",
    "outDir": "build/develop"
  },
  "files": [
    "app/app.d.ts",
    "app/unit_test.d.ts"
  ],
  "include": [
    "app/**/*.*"
  ],
  "exclude": [
    "app/vendor/**/*.*"
  ],
  "compileOnSave": false
}

Actual behavior:

We have pretty large typescript project and rely on watch mode of typescript to compile changes as we develop and save these. Problem is - incremental compilation takes very long time.

What is interesting is that TSServer returns errors almost immediately (I am using VIM plugin tsuquyomi.) I know that originally reason to parse everything is to make sure output is consistent, but may be it makes sense to introduce "light" checks which verifies only currently changed file(s)?

Files:          1521
Lines:        337399
Nodes:       1925827
Identifiers:  596716
Symbols:      383096
Types:        146778
Memory used: 952291K
I/O read:      0.60s
I/O write:     1.26s
Parse time:    6.58s
Bind time:     2.19s
Check time:   11.63s
Emit time:     8.83s
Total time:   29.25s
4:58:38 PM - Compilation complete. Watching for file changes.
4:58:49 PM - File change detected. Starting incremental compilation...
Files:           1521
Lines:         337398
Nodes:        1925827
Identifiers:   596716
Symbols:       383096
Types:         146778
Memory used: 1032513K
I/O read:       0.00s
I/O write:      0.30s
Parse time:     2.75s
Bind time:      0.02s
Check time:    12.24s
Emit time:     14.05s
Total time:    29.06s
4:59:18 PM - Compilation complete. Watching for file changes.

[normalser]

FYI #10879

[mhegazy]

Please find relevant discussions in #13538