Mercurial optional

repo2docker/contentproviders/mercurial.py

@@ -1,8 +1,39 @@
 import subprocess
+import os
+from distutils.util import strtobool
 
 from .base import ContentProvider, ContentProviderException
 from ..utils import execute_cmd
 
+HG_EVOLVE_REQUIRED = strtobool(
+    os.environ.get("REPO2DOCKER_HG_EVOLVE_REQUIRED", "False")
+)
+
+if HG_EVOLVE_REQUIRED:
+    if "REPO2DOCKER_HG_REQUIRED" in os.environ:
+        HG_REQUIRED = strtobool(os.environ["REPO2DOCKER_HG_REQUIRED"])
+        if not HG_REQUIRED:
+            raise ValueError(
+                "Incompatible values for environment variables "
+                "REPO2DOCKER_HG_EVOLVE_REQUIRED=1 and REPO2DOCKER_HG_REQUIRED=0"
+            )
+    else:
+        HG_REQUIRED = True
+else:
+    HG_REQUIRED = strtobool(os.environ.get("REPO2DOCKER_HG_REQUIRED", "False"))
+
+
+def is_mercurial_available():
+    try:
+        subprocess.check_output(["hg", "version"])
+    except subprocess.CalledProcessError:
+        return False
+    return True
+
+
+if HG_REQUIRED and not is_mercurial_available():
+    raise RuntimeError("REPO2DOCKER_HG_REQUIRED but the command `hg` is not available")
+
 
 class Mercurial(ContentProvider):
     """Provide contents of a remote Mercurial repository."""
@@ -16,6 +47,8 @@ class Mercurial(ContentProvider):
                 stderr=subprocess.DEVNULL,
             )
         except subprocess.CalledProcessError:
+            # warning: if hg is not installed and `not HG_REQUIRED`,
+            # we return None even for a hg repo
             return None
 
         return {"repo": source, "ref": ref}
@@ -26,7 +59,14 @@ class Mercurial(ContentProvider):
 
         # make a clone of the remote repository
         try:
-            cmd = ["hg", "clone", repo, output_dir]
+            cmd = [
+                "hg",
+                "clone",
+                repo,
+                output_dir,
+                "--config",
+                "phases.publish=False",
+            ]
             if ref is not None:
                 # don't update so the clone will include an empty working
                 # directory, the given ref will be updated out later
@@ -35,9 +75,9 @@ class Mercurial(ContentProvider):
                 yield line
 
         except subprocess.CalledProcessError as error:
-            msg = "Failed to clone repository from {repo}".format(repo=repo)
+            msg = f"Failed to clone repository from {repo}"
             if ref is not None:
-                msg += " (ref {ref})".format(ref=ref)
+                msg += f" (ref {ref})"
             msg += "."
             raise ContentProviderException(msg) from error
 

tests/unit/contentproviders/test_mercurial.py

@@ -5,6 +5,29 @@ from tempfile import TemporaryDirectory
 import pytest
 
 from repo2docker.contentproviders import Mercurial
+from repo2docker.contentproviders.mercurial import (
+    HG_REQUIRED,
+    HG_EVOLVE_REQUIRED,
+    is_mercurial_available,
+)
+
+skip_if_no_hg = pytest.mark.skipif(
+    not HG_REQUIRED and not is_mercurial_available(),
+    reason="not HG_REQUIRED and Mercurial not available",
+)
+
+
+def is_evolve_available():
+    if not is_mercurial_available():
+        return False
+    output = subprocess.getoutput("hg version -v")
+    return " evolve " in output
+
+
+EVOLVE_AVAILABLE = is_evolve_available()
+
+if HG_EVOLVE_REQUIRED and not EVOLVE_AVAILABLE:
+    raise RuntimeError("HG_EVOLVE_REQUIRED and not EVOLVE_AVAILABLE")
 
 
 def _add_content_to_hg(repo_dir):
@@ -16,6 +39,14 @@ def _add_content_to_hg(repo_dir):
     subprocess.check_call(["hg", "add", "test"], cwd=repo_dir)
     subprocess.check_call(["hg", "commit", "-m", "Test commit"], cwd=repo_dir)
 
+    if EVOLVE_AVAILABLE:
+        subprocess.check_call(["hg", "topic", "test-topic"], cwd=repo_dir)
+        subprocess.check_call(
+            ["hg", "commit", "-m", "Test commit in topic test-topic"],
+            cwd=repo_dir,
+        )
+        subprocess.check_call(["hg", "up", "default"], cwd=repo_dir)
+
 
 def _get_node_id(repo_dir):
     """Get repository's current commit node ID (currently SHA1)."""
@@ -46,6 +77,7 @@ def hg_repo_with_content(hg_repo):
     yield hg_repo, node_id
 
 
+@skip_if_no_hg
 def test_detect_mercurial(hg_repo_with_content, repo_with_content):
     mercurial = Mercurial()
     assert mercurial.detect("this-is-not-a-directory") is None
@@ -58,6 +90,7 @@ def test_detect_mercurial(hg_repo_with_content, repo_with_content):
     assert mercurial.detect(hg_repo) == {"repo": hg_repo, "ref": None}
 
 
+@skip_if_no_hg
 def test_clone(hg_repo_with_content):
     """Test simple hg clone to a target dir"""
     upstream, node_id = hg_repo_with_content
@@ -72,9 +105,10 @@ def test_clone(hg_repo_with_content):
         assert mercurial.content_id == node_id
 
 
+@skip_if_no_hg
 def test_bad_ref(hg_repo_with_content):
     """
-    Test trying to checkout a ref that doesn't exist
+    Test trying to update to a ref that doesn't exist
     """
     upstream, node_id = hg_repo_with_content
     with TemporaryDirectory() as clone_dir:
@@ -82,3 +116,30 @@ def test_bad_ref(hg_repo_with_content):
         with pytest.raises(ValueError):
             for _ in Mercurial().fetch(spec, clone_dir):
                 pass
+
+
+@pytest.mark.skipif(
+    not HG_EVOLVE_REQUIRED and not EVOLVE_AVAILABLE,
+    reason="not HG_EVOLVE_REQUIRED and hg-evolve not available",
+)
+@skip_if_no_hg
+def test_ref_topic(hg_repo_with_content):
+    """
+    Test trying to update to a topic
+    """
+    upstream, node_id = hg_repo_with_content
+    node_id = subprocess.Popen(
+        ["hg", "identify", "-i", "-r", "topic(test-topic)"],
+        stdout=subprocess.PIPE,
+        cwd=upstream,
+    )
+    node_id = node_id.stdout.read().decode().strip()
+
+    with TemporaryDirectory() as clone_dir:
+        spec = {"repo": upstream, "ref": "test-topic"}
+        mercurial = Mercurial()
+        for _ in mercurial.fetch(spec, clone_dir):
+            pass
+        assert (Path(clone_dir) / "test").exists()
+
+        assert mercurial.content_id == node_id