I have written my test code as follows.

`Describe 'extract-delta.sh'
Include lib/extract-delta.sh

setup_environment() {
export EXTRACT_DELTA_CONSOLE_LOG_PATH="/tmp/test/extract-delta-console-log"
export MINIMIZED_CHECKOUT_ROOT="/tmp/test/minimized-checkout-root"
export MINIMIZED_CHECKOUT_REF="test-branch"
export CHECKOUT_ROOT="/tmp/test/checkout-root"
export CHECKOUT_REF="test-branch" # Explicitly set this to match the script
export TO_REVISION="test-to-revision"
export FROM_REVISION="test-from-revision"
export EXTRACTED_DELTA_ROOT="/tmp/test/extracted-delta-root"
export POD_NAME="test-pod"
export RESULTS_FROM_COMMIT_PATH="/tmp/test/results-from-commit"
export RESULTS_TO_COMMIT_PATH="/tmp/test/results-to-commit"
export RESULTS_EXTRACTED_DELTA_REF_PATH="/tmp/test/results-extracted-delta-ref"

# Create the necessary directories
mkdir -p "$EXTRACT_DELTA_CONSOLE_LOG_PATH"
mkdir -p "$MINIMIZED_CHECKOUT_ROOT/$MINIMIZED_CHECKOUT_REF"
mkdir -p "$CHECKOUT_ROOT/$CHECKOUT_REF"  # This directory must be created to avoid cd errors
mkdir -p "$EXTRACTED_DELTA_ROOT/$POD_NAME"
mkdir -p "$(dirname "$RESULTS_FROM_COMMIT_PATH")"
mkdir -p "$(dirname "$RESULTS_TO_COMMIT_PATH")"
mkdir -p "$(dirname "$RESULTS_EXTRACTED_DELTA_REF_PATH")"

}

cleanup_environment() {
rm -rf /tmp/test/
}

BeforeEach 'setup_environment'
AfterEach 'cleanup_environment'

Mock_git() {
case "$1" in
checkout)
echo "Checked out to $2"
;;
rev-parse)
case "$2" in
"$FROM_REVISION") echo "from-commit-sha" ;;
"$TO_REVISION") echo "to-commit-sha" ;;
*) echo "Unknown revision" ;;
esac
;;
diff)
echo "file1.txt"
echo "file2.txt"
;;
*)
echo "Unknown command"
;;
esac
}

Replace the actual git command with the mock

BeforeEach 'alias git=Mock_git'
AfterEach 'unalias git'

It "runs the script and logs correctly"
When run script "lib/extract-delta.sh"
The status should be success
The output should include "step start"
The output should include "Checked out to test-to-revision"
The output should include "file1.txt - included"
The output should include "file2.txt - included"
The output should include "step completion"
End

It "creates expected files"
When run script "lib/extract-delta.sh"
The file "$RESULTS_FROM_COMMIT_PATH" should be present
The file "$RESULTS_TO_COMMIT_PATH" should be present
The file "$RESULTS_EXTRACTED_DELTA_REF_PATH" should be present
The contents of file "$RESULTS_FROM_COMMIT_PATH" should equal "from-commit-sha"
The contents of file "$RESULTS_TO_COMMIT_PATH" should equal "to-commit-sha"
The contents of file "$RESULTS_EXTRACTED_DELTA_REF_PATH" should equal "test-pod"
End

Move the file setup outside of the It block

Describe 'File copying test'
Before 'setup_environment'
Before 'touch "$CHECKOUT_ROOT/$CHECKOUT_REF/file1.txt"'
Before 'touch "$MINIMIZED_CHECKOUT_ROOT/$MINIMIZED_CHECKOUT_REF/file1.txt"'
Before 'touch "$CHECKOUT_ROOT/$CHECKOUT_REF/file2.txt"'
Before 'touch "$MINIMIZED_CHECKOUT_ROOT/$MINIMIZED_CHECKOUT_REF/file2.txt"'

It "copies the correct files"
  When run script "lib/extract-delta.sh"
  The file "$EXTRACTED_DELTA_ROOT/$POD_NAME/file1.txt" should be present
  The file "$EXTRACTED_DELTA_ROOT/$POD_NAME/file2.txt" should be present
End

End
End
`

When i run it it gives me the error 'fatal: not a git repository (or any of the parent directories): .git' but I have already creayed the git mock function in my test script :(

It would be great if anyone can give pointers on this to overcome this issue :(

Following is an extraction of the error
`1, step start: 2024-08-29T12:51:44Z
fatal: not a git repository (or any of the parent directories): .git
Running: /bin/sh [bash 5.2.26(1)-release]
FFW

Examples:

1. extract-delta.sh runs the script and logs correctly
   When run script lib/extract-delta.sh

   1.1) The output should include Checked out to test-to-revision

      expected "step start: 2024-08-29T12:51:45Z
      fatal: not a git repository (or any of the parent directories): .git
      fatal: not a git repository (or any of the parent directories): .git
      fatal: not a git repository (or any of the parent directories): .git
      warning: Not a git repository. Use --no-index to compare two paths outside a working tree`