activate.fish: support activating conda in fish shells (#342)

Co-authored-by: Uwe L. Korn <xhochy@users.noreply.github.com>

.github/workflows/main.yml

@@ -86,11 +86,11 @@ jobs:
         include:
           # include the appropriate dependencies for testing SquashFS on each OS
           - os: macos-12
-            squashfs_deps: "conda-forge::squashfs-tools"
+            conda_deps: "conda-forge::squashfs-tools conda-forge::fish"
           - os: ubuntu-latest
-            squashfs_deps: "conda-forge::squashfs-tools conda-forge::squashfuse"
+            conda_deps: "conda-forge::squashfs-tools conda-forge::squashfuse conda-forge::fish"
           - os: windows-latest
-            squashfs_deps: ""
+            conda_deps: ""
     steps:
     - name: Retrieve the source code
       uses: actions/checkout@v4
@@ -118,7 +118,7 @@ jobs:
         source $CONDA_ROOT/etc/profile.d/conda.sh
         conda info -a
         mv conda-bld $CONDA_ROOT/conda-bld
-        conda create -n cptest local::conda-pack conda-forge::pytest conda-forge::pytest-cov defaults::python=${{ matrix.pyver }} ${{ matrix.squashfs_deps }}
+        conda create -n cptest local::conda-pack conda-forge::pytest conda-forge::pytest-cov defaults::python=${{ matrix.pyver }} ${{ matrix.conda_deps }}
         conda activate cptest
         pytest -v -ss --cov=conda_pack --cov-branch --cov-report=xml conda_pack/tests
     - uses: codecov/codecov-action@v4

conda_pack/core.py

@@ -42,7 +42,9 @@ class CondaPackException(Exception):
     _scripts = [(os.path.join(_current_dir, 'scripts', 'posix', 'activate'),
                  os.path.join(BIN_DIR, 'activate')),
                 (os.path.join(_current_dir, 'scripts', 'posix', 'deactivate'),
-                 os.path.join(BIN_DIR, 'deactivate'))]
+                 os.path.join(BIN_DIR, 'deactivate')),
+                (os.path.join(_current_dir, 'scripts', 'posix', 'activate.fish'),
+                 os.path.join(BIN_DIR, 'activate.fish'))]
 
 
 class _Context:

conda_pack/scripts/posix/activate.fish

@@ -0,0 +1,62 @@
+function _activate
+    set -l full_path_script_dir (cd (dirname (status -f)); and pwd)
+    set -l full_path_env (dirname "$full_path_script_dir")
+    set env_name (basename "$full_path_env")
+
+    # If there's already a source env
+    if [ -n "$CONDA_PREFIX" ]
+        # If the source env differs from this env
+        if [ "$CONDA_PREFIX" != "$full_path_env" ]
+            deactivate
+        else
+            return 0  # nothing to do
+        end
+    end
+
+    export CONDA_PREFIX="$full_path_env"
+    set _OLD_PATH "$PATH"
+    set PATH "$full_path_env/bin:$PATH"
+
+    functions -c fish_prompt _old_fish_prompt
+    function fish_prompt
+        # Run the user's prompt first; it might depend on (pipe)status.
+        set -l prompt (_old_fish_prompt)
+
+        printf "($env_name) "
+
+        string join -- \n $prompt # handle multi-line prompts
+    end
+
+    # Run the activate scripts
+    set -l _script_dir "$full_path_env/etc/conda/activate.d"
+    if [ -d "$_script_dir" ] && [ -n "(ls -A "$_script_dir")" ]
+        set -l _path
+        for _path in "$_script_dir"/*.sh
+            # Normally these are sourced but given they're not-fish scripts it will
+            # error out. Run them anyways for any side effects.
+            sh "$_path"
+        end
+        for _path in "$_script_dir"/*.fish
+            . "$_path"
+        end
+    end
+end
+
+function deactivate -d 'Exit conda mode and return to the normal environment.'
+    # reset old environment variables
+    if test -n "$_OLD_PATH"
+        set -gx PATH $_OLD_PATH
+        set -e _OLD_PATH
+    end
+
+    if functions -q _old_fish_prompt
+        # Erase virtualenv's `fish_prompt` and restore the original.
+        functions -e fish_prompt
+        functions -c _old_fish_prompt fish_prompt
+        functions -e _old_fish_prompt
+    end
+
+    set -e CONDA_PREFIX
+end
+
+_activate

conda_pack/tests/test_core.py

@@ -509,7 +509,7 @@ def test_pack(tmpdir, py37_env):
         fnames = ('conda-unpack.exe', 'conda-unpack-script.py',
                   'activate.bat', 'deactivate.bat')
     else:
-        fnames = ('conda-unpack', 'activate', 'deactivate')
+        fnames = ('conda-unpack', 'activate', 'deactivate', 'activate.fish')
     assert diff == {os.path.join(BIN_DIR_L, f) for f in fnames}
 
 
@@ -622,6 +622,7 @@ def test_activate(tmpdir):
         assert out == 'CONDAPACK_ACTIVATED=1\r\nCONDAPACK_ACTIVATED=\r\nDone\r\n'
 
     else:
+        # bash
         command = (". {path}/bin/activate && "
                    "test $CONDAPACK_ACTIVATED -eq 1 && "
                    ". {path}/bin/deactivate && "
@@ -632,3 +633,14 @@ def test_activate(tmpdir):
                                       stderr=subprocess.STDOUT).decode()
 
         assert out == 'Done\n'
+
+        # fish
+        command = (". {path}/bin/activate.fish && "
+                   "python -c 'import sys; print(sys.executable)' && "
+                   "deactivate && "
+                   "echo 'Done'").format(path=extract_path)
+
+        out = subprocess.check_output(['/usr/bin/env', 'fish', '-c', command],
+                                      stderr=subprocess.STDOUT).decode()
+        assert "test_activate0" in out
+        assert "Done\n" in out