should work on ci now

snuba/migrations/autogeneration/main.py

@@ -1,13 +1,11 @@
 import os
 import subprocess
 
-import yaml
-
 
 def generate(storage_path: str) -> tuple[str, str]:
-    storage_path = os.path.abspath(os.path.expanduser(storage_path))
+    storage_path = os.path.realpath(os.path.abspath(os.path.expanduser(storage_path)))
 
-    # get the version of the storage at HEAD
+    # get the version of the file at HEAD
     try:
         repo_path = (
             subprocess.run(
@@ -23,27 +21,18 @@ def generate(storage_path: str) -> tuple[str, str]:
             .stdout.decode("utf-8")
             .strip()
         )
-        if not repo_path.endswith("snuba"):
-            raise ValueError(
-                "expected git repo to end with 'snuba' but got: " + repo_path
-            )
-        assert storage_path.startswith(repo_path)  # should always hold
-        rel_storage_path = storage_path[len(repo_path) + 1 :]
-        old_storage = (
-            subprocess.run(
-                ["git", "show", f"HEAD:{rel_storage_path}"],
-                capture_output=True,
-                check=True,
-            )
-            .stdout.decode("utf-8")
-            .strip()
-        )
+        repo_rel_path = os.path.relpath(storage_path, repo_path)
+        old_storage = subprocess.run(
+            ["git", "show", f"HEAD:{repo_rel_path}"],
+            cwd=repo_path,
+            capture_output=True,
+            check=True,
+        ).stdout.decode("utf-8")
     except subprocess.CalledProcessError as e:
         raise ValueError(e.stderr.decode("utf-8")) from e
-    old_storage = yaml.safe_load(old_storage)
 
     # get the user-provided (modified) storage
     with open(storage_path, "r") as f:
-        new_storage = yaml.safe_load(f)
+        new_storage = f.read()
 
     return old_storage, new_storage

tests/migrations/test_autogeneration.py

@@ -1,15 +1,42 @@
-import pytest
+import os
+import subprocess
 
 from snuba.migrations.autogeneration import generate
 
 
 def test_basic() -> None:
-    old_storage, new_storage = generate(
-        "snuba/datasets/configuration/events/storages/errors.yaml"
-    )
-    assert old_storage, new_storage
+    dir = "/tmp/kylesfakerepo987636"
+    fname = "fakestorage.yaml"
 
+    # make a tmp dir with a git repo
+    if os.path.exists(dir):
+        subprocess.run(["rm", "-rf", dir], check=True)
+    os.makedirs(dir)
+    try:
+        subprocess.run(["git", "init"], cwd=dir, check=True)
+        # make a fake storage
+        with open(os.path.join(dir, fname), "w") as f:
+            f.write("hello world\n")
+        subprocess.run(
+            ["git", "add", "."],
+            cwd=dir,
+            check=True,
+        )
+        subprocess.run(
+            ["git", "commit", "-m", '"blop"'],
+            cwd=dir,
+            check=True,
+        )
+    except subprocess.CalledProcessError as e:
+        if not e.stderr:
+            raise
+        raise ValueError(e.stderr.decode("utf-8")) from e
 
-def test_error() -> None:
-    with pytest.raises(ValueError):
-        generate("~/hello.txt")
+    # update the fake storage
+    with open(os.path.join(dir, fname), "a") as f:
+        f.write("goodbye world")
+
+    # make sure HEAD and curr version looks right
+    old_storage, new_storage = generate(os.path.join(dir, fname))
+    assert old_storage == "hello world\n"
+    assert new_storage == "hello world\ngoodbye world"