Github action check if a file already exists - file

Question

I have the following git action which allows me to download an image.
I have to make sure if the file already exists to skip the "Commit file" and the "Push changes"
How can I check if the file already exists if it already exists nothing is done.
on:
workflow_dispatch:
name: Scrape File
jobs:
build:
name: Build
runs-on: ubuntu-latest
steps:
- uses: actions/checkout#v2
name: Check out current commit
- name: Url
run: |
URL=$(node ./action.js)
echo $URL
echo "URL=$URL" >> $GITHUB_ENV
- uses: suisei-cn/actions-download-file#v1
id: downloadfile
name: Download the file
with:
url: ${{ env.URL }}
target: assets/
- run: ls -l 'assets/'
- name: Commit files
run: |
git config --local user.email "41898282+github-actions[bot]#users.noreply.github.com"
git config --local user.name "github-actions[bot]"
git add .
git commit -m "Add changes" -a
- name: Push changes
uses: ad-m/github-push-action#master
with:
github_token: ${{ secrets.GITHUB_TOKEN }}
branch: ${{ github.ref }}

Answer 1

There are a few options here - you can go directly with bash and do something like this:
if test -f "$FILE"; then
#file exists
fi
or use one of the existing actions like this:
- name: Check file existence
id: check_files
uses: andstor/file-existence-action#v1
with:
files: "assets/${{ env.URL }}"
- name: File exists
if: steps.check_files.outputs.files_exists == 'true'
run: echo "It exists !"

Answer 2

WARNING: Linux (and maybe MacOS) only solution ahead!
I was dealing with a very similar situation some time earlier and developed a method to not just check for added files, but also will be useful if you wanted to check for modified or deleted files or directories as well.
Warning:
This solution works only if the file is added/modified/deleted in git repository.
Introduction:
The command git status --short will return list of untracked, , deleted and modified files. For example:-
D deleted_foo
M modified_foo
?? untracked_dir_foo/
?? untracked_file_foo
A tracked_n_added_foo
Note that we run the same command as git status -s.
Understanding `git status -s` output:
When you read the output, you will see some lines in this form:
** filename
** dirname/
Note that here ** represent the first word of the line (ones like D, ?? etc.).
Here is a summary of all ** in the lines:
**
Meaning
D
File/dir has been deleted.
M
File/dir has been modified.
??
File/dir has been added but not tracked using git add [FILENAME].
A
File/dir has been added and also tracked using git add [FILENAME].
NOTE: Take care of the spaces! Using, for example, M instead of M in the following solution will not work as expected!
Solution:
Shell part of solution:
We can grep the output of git status -s to check whether a file/dir was added/modified/deleted.
The shell part of the solution goes like this:
if git status -s | grep -x "** [FILENAME]"; then
# Do whatever you wanna on match
else
# Do whatever you wanna on no-match
fi
Note: Get desired ** from the table above and replace [FILENAME] with filename.
For example, to check whether a file named foo was modified, use:
git status -s | grep -x " M foo"
Explanation: We use git status -s to get the output and pipe the output to grep. We also use command line option -x with grep so as to match whole line.
Workflow part of solution:
A very simple solution will go like this:
...
- name: Check for file
id: file_check
run: |
if git status -s | grep -x "** [FILENAME]"; then
echo "check_result=true" >> $GITHUB_OUTPUT
else
echo "check_result=false" >> $GITHUB_OUTPUT
fi
...
- name: Run dependent step
if: steps.file_check.outputs.check_result == 'true'
run: |
# Do whatever you wanna do on file found to be
# added/modified/deleted, based on what you set '**' to
...