From c95dff82bf65456fe50ad4158c0ddea750bff719 Mon Sep 17 00:00:00 2001
From: Ken Odegard <kodegard@anaconda.com>
Date: Wed, 17 Apr 2024 19:35:44 -0500
Subject: [PATCH 1/2] Add tests

---
 tests/test_variants.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/test_variants.py b/tests/test_variants.py
index 71b2e7e627..e853f172fd 100644
--- a/tests/test_variants.py
+++ b/tests/test_variants.py
@@ -17,6 +17,8 @@
     combine_specs,
     dict_of_lists_to_list_of_dicts,
     filter_combined_spec_to_used_keys,
+    find_used_variables_in_batch_script,
+    find_used_variables_in_shell_script,
     get_package_variants,
     get_vars,
     validate_spec,
@@ -715,3 +717,25 @@ def test_get_vars():
     ]
 
     assert get_vars(variants) == {"nodejs"}
+
+
+def test_find_used_variables_in_shell_script(tmp_path: Path) -> None:
+    variants = ("FOO", "BAR", "BAZ", "QUX")
+    (script := tmp_path / "script.sh").write_text(
+        f"${variants[0]}\n"
+        f"${{{variants[1]}}}\n"
+        f"${{{{{variants[2]}}}}}\n"
+        f"$${variants[3]}\n"
+    )
+    assert find_used_variables_in_shell_script(variants, script) == {"FOO", "BAR"}
+
+
+def test_find_used_variables_in_batch_script(tmp_path: Path) -> None:
+    variants = ("FOO", "BAR", "BAZ", "QUX")
+    (script := tmp_path / "script.sh").write_text(
+        f"%{variants[0]}%\n"
+        f"%%{variants[1]}%%\n"
+        f"${variants[2]}\n"
+        f"${{{variants[3]}}}\n"
+    )
+    assert find_used_variables_in_batch_script(variants, script) == {"FOO", "BAR"}

From 5381d970400916f702cbcd01c5c984056437bbee Mon Sep 17 00:00:00 2001
From: Ken Odegard <kodegard@anaconda.com>
Date: Wed, 17 Apr 2024 20:40:18 -0500
Subject: [PATCH 2/2] Refactor find_used_variables_*

---
 conda_build/variants.py | 53 +++++++++++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/conda_build/variants.py b/conda_build/variants.py
index be59e36603..b09206ac66 100644
--- a/conda_build/variants.py
+++ b/conda_build/variants.py
@@ -12,6 +12,7 @@
 from copy import copy
 from functools import lru_cache
 from itertools import product
+from pathlib import Path
 from typing import TYPE_CHECKING
 
 import yaml
@@ -766,23 +767,39 @@ def find_used_variables_in_text(variant, recipe_text, selectors_only=False):
     return used_variables
 
 
-def find_used_variables_in_shell_script(variant, file_path):
-    with open(file_path) as f:
-        text = f.read()
-    used_variables = set()
-    for v in variant:
-        variant_regex = rf"(^[^$]*?\$\{{?\s*{re.escape(v)}\s*[\s|\}}])"
-        if re.search(variant_regex, text, flags=re.MULTILINE | re.DOTALL):
-            used_variables.add(v)
-    return used_variables
+def find_used_variables_in_shell_script(
+    variants: Iterable[str],
+    file_path: str | os.PathLike | Path,
+) -> set[str]:
+    text = Path(file_path).read_text()
+    return {
+        variant
+        for variant in variants
+        if (
+            variant in text  # str in str is faster than re.search
+            and re.search(
+                rf"(^[^$]*?\$\{{?\s*{re.escape(variant)}\s*[\s|\}}])",
+                text,
+                flags=re.MULTILINE | re.DOTALL,
+            )
+        )
+    }
 
 
-def find_used_variables_in_batch_script(variant, file_path):
-    with open(file_path) as f:
-        text = f.read()
-    used_variables = set()
-    for v in variant:
-        variant_regex = rf"\%{re.escape(v)}\%"
-        if re.search(variant_regex, text, flags=re.MULTILINE | re.DOTALL):
-            used_variables.add(v)
-    return used_variables
+def find_used_variables_in_batch_script(
+    variants: Iterable[str],
+    file_path: str | os.PathLike | Path,
+) -> set[str]:
+    text = Path(file_path).read_text()
+    return {
+        variant
+        for variant in variants
+        if (
+            variant in text  # str in str is faster than re.search
+            and re.search(
+                rf"\%{re.escape(variant)}\%",
+                text,
+                flags=re.MULTILINE | re.DOTALL,
+            )
+        )
+    }