fix: select_spark_version(latest=True) no longer implicitly filters to scala 2.12

The scala parameter defaulted to "2.12" and the filter applied it
unconditionally, so select_spark_version(latest=True) silently
narrowed to scala-2.12 runtimes before picking the latest instead of
considering every scala version.

This diverged from the Go SDK this logic is ported from: Go's
SparkVersionRequest.Scala has no default, so an unset Scala is ""
(its zero value), and strings.Contains(key, "-scala"+"") matches
every version's key -- Go's real default is no scala filter.

Changed the Python default to "" and only apply the filter when
scala is truthy, matching the Go SDK's actual behavior. Callers who
explicitly pass scala="2.12" are unaffected.

Fixes #1487

Author: mittalpk

databricks/sdk/mixins/compute.py

@@ -81,7 +81,7 @@ def select_spark_version(
         ml: bool = False,
         genomics: bool = False,
         gpu: bool = False,
-        scala: str = "2.12",
+        scala: str = "",
         spark_version: str = None,
         photon: bool = False,
         graviton: bool = False,
@@ -95,17 +95,19 @@ def select_spark_version(
         :param genomics: bool
         :param gpu: bool
         :param scala: str
+            Scala version to filter on, e.g. "2.12" or "2.13". Leave empty (the default) to
+            consider every Scala version, matching the Go SDK's zero-value behavior.
         :param spark_version: str
         :param photon: bool
         :param graviton: bool
 
         :returns: `spark_version` compatible string
         """
-        # Logic ported from https://github.com/databricks/databricks-sdk-go/blob/main/service/compute/spark_version.go
+        # Logic ported from https://github.com/databricks/databricks-sdk-go/blob/main/service/compute/ext_spark_version.go
         versions = []
         sv = self.spark_versions()
         for version in sv.versions:
-            if "-scala" + scala not in version.key:
+            if scala and "-scala" + scala not in version.key:
                 continue
             matches = (
                 ("apache-spark-" not in version.key)

tests/test_compute_mixins.py

@@ -1,7 +1,16 @@
+import json
+
 import pytest
 
 from databricks.sdk.mixins.compute import SemVer
 
+SPARK_VERSIONS_RESPONSE = {
+    "versions": [
+        {"key": "16.4.x-scala2.12", "name": "16.4"},
+        {"key": "18.2.x-scala2.13", "name": "18.2"},
+    ]
+}
+
 
 @pytest.mark.parametrize(
     "given,expected",
@@ -40,3 +49,25 @@ def test_sorting_semver():
         SemVer(1, 0, 0),
         SemVer(12, 0, 0),
     ]
+
+
+def test_select_spark_version_latest_ignores_scala_by_default(w, requests_mock):
+    # Regression test for https://github.com/databricks/databricks-sdk-py/issues/1487:
+    # select_spark_version(latest=True) implicitly filtered to the "2.12" default
+    # scala version before picking the latest, instead of considering every scala
+    # version like the Go SDK it's ported from does.
+    requests_mock.get(
+        "http://localhost/api/2.1/clusters/spark-versions",
+        text=json.dumps(SPARK_VERSIONS_RESPONSE),
+    )
+
+    assert w.clusters.select_spark_version(latest=True) == "18.2.x-scala2.13"
+
+
+def test_select_spark_version_latest_still_honors_an_explicit_scala(w, requests_mock):
+    requests_mock.get(
+        "http://localhost/api/2.1/clusters/spark-versions",
+        text=json.dumps(SPARK_VERSIONS_RESPONSE),
+    )
+
+    assert w.clusters.select_spark_version(latest=True, scala="2.12") == "16.4.x-scala2.12"