Coverage not shown on typescript

Environment

1. node -v: v10.16.0

2. npm -v: 6.9.0 /yarn -v 1.17.3

3. npm ls jest

    npm ls jest
   180@1.0.0 /Users/jean/dev/startups/yupwego/src/vscode-jest-499
   └── jest@24.9.0
   

4. yarn why jest

   yarn why jest
   yarn why v1.17.3
   [1/4] 🤔  Why do we have the module "jest"...?
   [2/4] 🚚  Initialising dependency graph...
   [3/4] 🔍  Finding dependency...
   [4/4] 🚡  Calculating file sizes...
   => Found "jest@24.9.0"
   info Has been hoisted to "jest"
   info This module exists because it's specified in "devDependencies".
   info Disk size without dependencies: "48KB"
   info Disk size with unique dependencies: "276KB"
   info Disk size with transitive dependencies: "51.21MB"
   info Number of shared dependencies: 43
   ✨  Done in 0.57s.
   

5. your vscode-jest settings if customized:

   • “jest.showCoverageOnLoad”: true

6. Operating system: OSX Mojave 10.14.6

7. installed vscode extensions

code --list-extensions
AndrewRazumovsky.vscode-styled-jsx-languageserver
andys8.jest-snippets
Arjun.swagger-viewer
blanu.vscode-styled-jsx
christian-kohler.npm-intellisense
dbaeumer.vscode-eslint
DotJoshJohnson.xml
eamodio.gitlens
EditorConfig.EditorConfig
eg2.vscode-npm-script
eriklynd.json-tools
esbenp.prettier-vscode
file-icons.file-icons
joaompinto.asciidoctor-vscode
lightbend.vscode-sbt-scala
mrorz.language-gettext
ms-azuretools.vscode-docker
Orta.vscode-jest
PKief.material-icon-theme
ryu1kn.partial-diff
scala-lang.scala
scalameta.metals
skyran.js-jsx-snippets
stkb.rewrap
vscode-icons-team.vscode-icons
wayou.vscode-todo-highlight
xabikos.ReactSnippets

Prerequisite

• are you able to run jest test from command line?

  yarn jest
  yarn run v1.17.3
  $ /Users/jean/dev/startups/yupwego/src/vscode-jest-499/node_modules/.bin/jest
   PASS  src/capitalize/capitalize.test.ts
    capitalize
      ✓ should throw for null (4ms)
      ✓ should throw for things which aren't strings (1ms)
      ✓ should not change capitalized word (1ms)
      ✓ should capitalize the first letter of a lowercase word
      ✓ should lowercase the tail of an uppercase word (1ms)  
  
  ----------|----------|----------|----------|----------|-------------------|
  File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
  ----------|----------|----------|----------|----------|-------------------|
  All files |      100 |      100 |      100 |      100 |                   |
   index.ts |      100 |      100 |      100 |      100 |                   |
  ----------|----------|----------|----------|----------|-------------------|
  Test Suites: 1 passed, 1 total
  Tests:       5 passed, 5 total
  Snapshots:   0 total
  Time:        1.57s
  Ran all test suites.
  ✨  Done in 2.53s.
  

Steps to Reproduce

git clone https://github.com/jeantil/vscode-jest-499.git
cd vscode-jest-499
yarn install 
yarn jest
code .

Relevant Debug Info

I don’t see any errors in self-diagnosis output 😦

[Extension Host] spawning process with command=/Users/jean/dev/startups/yupwego/src/vscode-jest-499/node_modules/.bin/jest, args=--testLocationInResults,--json,--useStderr,--outputFile,/var/folders/gt/c0_8ryzj2m7fwmf07t68z0940000gn/T/jest_runner_vscode_jest_181.json,--watch,--no-color

Expected Behavior

overlay coverage on typescript code

Actual Behavior

No overlay appears. in some rare circumstances I can see the following code lens reporting coverage but it disapears as soon as anything changes

[mdebruijne]

The root cause for this issue is not in vscode-jest, but in Jest itself. Jest deletes the content of lcov.info when in watch mode and therefore code coverage doesn’t work. There are multiple issues reported about this (for example; https://github.com/facebook/jest/issues/7331).

There is a workaround to restore the functionality in vscode-jest;

Add this to VS Code settings.json;

{
  "jest.pathToJest": "npm run jest:watchAll --",
  "jest.runAllTestsFirst": false,
  "jest.showCoverageOnLoad": true
}

Add this to package.json

"scripts": {
  "jest:watchAll": "jest --watchAll",
}

(if you don’t have the coverage parameters in the Jest configuration file, then you need to add them to the CLI command; https://jestjs.io/docs/en/cli.html)

[Acanguven]

Changing --watch to --watchAll solved my problem.