Why does eslint fail on Github Actions but works locally?

Question

I have a workflow that looks like this

name: Node CI

on: [push]

jobs:
  build:

    runs-on: ubuntu-18.04

    steps:
    - uses: actions/checkout@v1
    - uses: actions/setup-node@v1
      with:
        node-version: '12.x'
    - run: npm install
    - run: npm run lint

For some reason the lint stage fails and produces the following error

> eslint . --ext .js,.jsx,.ts,.tsx


/home/runner/work/ABC/ABC/src/components/folder/Folder.tsx
##[error]  6:20  error  Missing file extension for "../../styles/Colors"        import/extensions
##[error]  6:20  error  Unable to resolve path to module '../../styles/Colors'  import/no-unresolved

/home/runner/work/ABC/ABC/src/components/todo/header/Heading.tsx
##[error]  4:20  error  Missing file extension for "../../../styles/Colors"        import/extensions
##[error]  4:20  error  Unable to resolve path to module '../../../styles/Colors'  import/no-unresolved


/home/runner/work/ABC/ABC/src/screens/TodoScreen.tsx
##[error]  3:20  error  Missing file extension for "../styles/Colors"        import/extensions
##[error]  3:20  error  Unable to resolve path to module '../styles/Colors'  import/no-unresolved

✖ 6 problems (6 errors, 0 warnings)

When I run npm run lint locally, it successfully passes.

I've tried running npm ci and then npm run lint and it still passes

Answer 1

Turns out this was a file case sensitivity issue.

../../styles/Colors was renamed earlier by me to ../../styles/colors (lowercase)

However for some reason git didn't pick this up. I had to do this manually with git mv