fix test in libs/python

this new function does not change chdir or sets environment

bundle/artifacts/whl/infer.go

@@ -16,12 +16,6 @@ type infer struct {
 func (m *infer) Apply(ctx context.Context, b *bundle.Bundle) diag.Diagnostics {
 	artifact := b.Config.Artifacts[m.name]
 
-	// TODO use python.DetectVEnvExecutable once bundle has a way to specify venv path
-	py, err := python.DetectExecutable(ctx)
-	if err != nil {
-		return diag.FromErr(err)
-	}
-
 	// Note: using --build-number (build tag) flag does not help with re-installing
 	// libraries on all-purpose clusters. The reason is that `pip` ignoring build tag
 	// when upgrading the library and only look at wheel version.
@@ -36,7 +30,9 @@ func (m *infer) Apply(ctx context.Context, b *bundle.Bundle) diag.Diagnostics {
 	//   version=datetime.datetime.utcnow().strftime("%Y%m%d.%H%M%S"),
 	// ...
 	//)
-	artifact.BuildCommand = fmt.Sprintf(`"%s" setup.py bdist_wheel`, py)
+
+	py := python.GetExecutable()
+	artifact.BuildCommand = fmt.Sprintf(`%s setup.py bdist_wheel`, py)
 
 	return nil
 }

bundle/config/mutator/python/python_mutator_test.go

@@ -541,7 +541,7 @@ func TestLoadDiagnosticsFile_nonExistent(t *testing.T) {
 
 func TestInterpreterPath(t *testing.T) {
 	if runtime.GOOS == "windows" {
-		assert.Equal(t, "venv\\Scripts\\python3.exe", interpreterPath("venv"))
+		assert.Equal(t, "venv\\Scripts\\python.exe", interpreterPath("venv"))
 	} else {
 		assert.Equal(t, "venv/bin/python3", interpreterPath("venv"))
 	}
@@ -673,7 +673,7 @@ func withFakeVEnv(t *testing.T, venvPath string) {
 
 func interpreterPath(venvPath string) string {
 	if runtime.GOOS == "windows" {
-		return filepath.Join(venvPath, "Scripts", "python3.exe")
+		return filepath.Join(venvPath, "Scripts", "python.exe")
 	} else {
 		return filepath.Join(venvPath, "bin", "python3")
 	}

internal/testutil/cmd.go

@@ -1,26 +0,0 @@
-package testutil
-
-import (
-	"bytes"
-	"os"
-	"os/exec"
-
-	"github.com/stretchr/testify/require"
-)
-
-func RunCommand(t TestingT, name string, args ...string) {
-	cmd := exec.Command(name, args...)
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-	require.NoError(t, cmd.Run())
-}
-
-func CaptureCommandOutput(t TestingT, name string, args ...string) string {
-	cmd := exec.Command(name, args...)
-	var stdout bytes.Buffer
-	cmd.Stdout = &stdout
-	cmd.Stderr = os.Stderr
-	err := cmd.Run()
-	require.NoError(t, err)
-	return stdout.String()
-}

internal/testutil/env.go

@@ -61,25 +61,3 @@ func Chdir(t TestingT, dir string) string {
 
 	return wd
 }
-
-func InsertPathEntry(t TestingT, path string) {
-	var separator string
-	if runtime.GOOS == "windows" {
-		separator = ";"
-	} else {
-		separator = ":"
-	}
-
-	t.Setenv("PATH", path+separator+os.Getenv("PATH"))
-}
-
-func InsertVirtualenvInPath(t TestingT, venvPath string) {
-	if runtime.GOOS == "windows" {
-		// https://github.com/pypa/virtualenv/commit/993ba1316a83b760370f5a3872b3f5ef4dd904c1
-		venvPath = filepath.Join(venvPath, "Scripts")
-	} else {
-		venvPath = filepath.Join(venvPath, "bin")
-	}
-
-	InsertPathEntry(t, venvPath)
-}

libs/python/detect.go

@@ -11,6 +11,19 @@ import (
 	"runtime"
 )
 
+// GetExecutable gets appropriate python binary name for the platform
+func GetExecutable() string {
+	// On Windows when virtualenv is created, the <env>/Scripts directory
+	// contains python.exe but no python3.exe.
+	// Most installers (e.g. the ones from python.org) only install python.exe and not python3.exe
+
+	if runtime.GOOS == "windows" {
+		return "python"
+	} else {
+		return "python3"
+	}
+}
+
 // DetectExecutable looks up the path to the python3 executable from the PATH
 // environment variable.
 //
@@ -26,31 +39,16 @@ func DetectExecutable(ctx context.Context) (string, error) {
 	//
 	// See https://github.com/pyenv/pyenv#understanding-python-version-selection
 
-	// On Windows when virtualenv is created, the <env>/Scripts directory
+	out, err := exec.LookPath(GetExecutable())
-	// contains python.exe but no python3.exe. However, system python does have python3 entry
-	// and it is also added to PATH, so it is found first.
-	if runtime.GOOS == "windows" {
-		out, err := exec.LookPath("python.exe")
-		if err == nil && out != "" {
-			return out, nil
-		}
-		if err != nil && !errors.Is(err, exec.ErrNotFound) {
-			return "", err
-		}
-	}
-
-	out, err := exec.LookPath("python3")
 
 	// most of the OS'es have python3 in $PATH, but for those which don't,
 	// we perform the latest version lookup
 	if err != nil && !errors.Is(err, exec.ErrNotFound) {
 		return "", err
 	}
-
 	if out != "" {
 		return out, nil
 	}
-
 	// otherwise, detect all interpreters and pick the least that satisfies
 	// minimal version requirements
 	all, err := DetectInterpreters(ctx)
@@ -71,7 +69,7 @@ func DetectExecutable(ctx context.Context) (string, error) {
 func DetectVEnvExecutable(venvPath string) (string, error) {
 	interpreterPath := filepath.Join(venvPath, "bin", "python3")
 	if runtime.GOOS == "windows" {
-		interpreterPath = filepath.Join(venvPath, "Scripts", "python3.exe")
+		interpreterPath = filepath.Join(venvPath, "Scripts", "python.exe")
 	}
 
 	if _, err := os.Stat(interpreterPath); err != nil {

libs/python/detect_test.go

@@ -39,7 +39,7 @@ func TestDetectVEnvExecutable_badLayout(t *testing.T) {
 
 func interpreterPath(venvPath string) string {
 	if runtime.GOOS == "windows" {
-		return filepath.Join(venvPath, "Scripts", "python3.exe")
+		return filepath.Join(venvPath, "Scripts", "python.exe")
 	} else {
 		return filepath.Join(venvPath, "bin", "python3")
 	}

libs/python/pythontest/pythontest.go

@@ -2,31 +2,106 @@ package pythontest
 
 import (
 	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
+	"testing"
 
 	"github.com/databricks/cli/internal/testutil"
-	"github.com/databricks/cli/libs/python"
 	"github.com/stretchr/testify/require"
 )
 
-func RequirePythonVENV(t testutil.TestingT, ctx context.Context, pythonVersion string, checkVersion bool) string {
+type VenvOpts struct {
-	tmpDir := t.TempDir()
+	// input
-	testutil.Chdir(t, tmpDir)
+	PythonVersion    string
+	skipVersionCheck bool
 
-	venvName := testutil.RandomName("test-venv-")
+	// input/output
-	testutil.RunCommand(t, "uv", "venv", venvName, "--python", pythonVersion, "--seed")
+	Dir  string
-	testutil.InsertVirtualenvInPath(t, filepath.Join(tmpDir, venvName))
+	Name string
 
-	pythonExe, err := python.DetectExecutable(ctx)
+	// output:
-	require.NoError(t, err)
+	// Absolute path to venv
-	require.Contains(t, pythonExe, venvName)
+	EnvPath string
 
-	if checkVersion {
+	// Absolute path to venv/bin or venv/Scripts, depending on OS
-		actualVersion := testutil.CaptureCommandOutput(t, pythonExe, "--version")
+	BinPath string
-		expectVersion := "Python " + pythonVersion
+
-		require.True(t, strings.HasPrefix(actualVersion, expectVersion), "Running %s --version: Expected %v, got %v", pythonExe, expectVersion, actualVersion)
+	// Absolute path to python binary
+	PythonExe string
+}
+
+func CreatePythonEnv(opts *VenvOpts) error {
+	if opts == nil || opts.PythonVersion == "" {
+		return errors.New("PythonVersion must be provided")
+	}
+	if opts.Name == "" {
+		opts.Name = testutil.RandomName("test-venv-")
 	}
 
-	return tmpDir
+	cmd := exec.Command("uv", "venv", opts.Name, "--python", opts.PythonVersion, "--seed", "-q")
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Dir = opts.Dir
+	err := cmd.Run()
+	if err != nil {
+		return err
+	}
+
+	opts.EnvPath, err = filepath.Abs(filepath.Join(opts.Dir, opts.Name))
+	if err != nil {
+		return err
+	}
+
+	_, err = os.Stat(opts.EnvPath)
+	if err != nil {
+		return fmt.Errorf("cannot stat EnvPath %s: %s", opts.EnvPath, err)
+	}
+
+	if runtime.GOOS == "windows" {
+		// https://github.com/pypa/virtualenv/commit/993ba1316a83b760370f5a3872b3f5ef4dd904c1
+		opts.BinPath = filepath.Join(opts.EnvPath, "Scripts")
+		opts.PythonExe = filepath.Join(opts.BinPath, "python.exe")
+	} else {
+		opts.BinPath = filepath.Join(opts.EnvPath, "bin")
+		opts.PythonExe = filepath.Join(opts.BinPath, "python3")
+	}
+
+	_, err = os.Stat(opts.BinPath)
+	if err != nil {
+		return fmt.Errorf("cannot stat BinPath %s: %s", opts.BinPath, err)
+	}
+
+	_, err = os.Stat(opts.PythonExe)
+	if err != nil {
+		return fmt.Errorf("cannot stat PythonExe %s: %s", opts.PythonExe, err)
+	}
+
+	if !opts.skipVersionCheck {
+		cmd := exec.Command(opts.PythonExe, "--version")
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("Failed to run %s --version: %s", opts.PythonExe, err)
+		}
+		outString := string(out)
+		expectVersion := "Python " + opts.PythonVersion
+		if !strings.HasPrefix(outString, expectVersion) {
+			return fmt.Errorf("Unexpected output from %s --version: %v (expected %v)", opts.PythonExe, outString, expectVersion)
+		}
+	}
+
+	return nil
+}
+
+func RequireActivatedPythonEnv(t *testing.T, ctx context.Context, opts *VenvOpts) {
+	err := CreatePythonEnv(opts)
+	require.NoError(t, err)
+	require.DirExists(t, opts.BinPath)
+
+	newPath := fmt.Sprintf("%s%c%s", opts.BinPath, os.PathListSeparator, os.Getenv("PATH"))
+	t.Setenv("PATH", newPath)
 }

libs/python/pythontest/pythontest_test.go

@@ -2,15 +2,42 @@ package pythontest
 
 import (
 	"context"
+	"os/exec"
+	"path/filepath"
 	"testing"
+
+	"github.com/databricks/cli/libs/python"
+	"github.com/stretchr/testify/require"
 )
 
-func TestVenv(t *testing.T) {
+func TestVenvSuccess(t *testing.T) {
 	// Test at least two version to ensure we capture a case where venv version does not match system one
 	for _, pythonVersion := range []string{"3.11", "3.12"} {
 		t.Run(pythonVersion, func(t *testing.T) {
 			ctx := context.Background()
-			RequirePythonVENV(t, ctx, pythonVersion, true)
+			dir := t.TempDir()
+			opts := VenvOpts{
+				PythonVersion: pythonVersion,
+				Dir:           dir,
+			}
+			RequireActivatedPythonEnv(t, ctx, &opts)
+			require.DirExists(t, opts.EnvPath)
+			require.DirExists(t, opts.BinPath)
+			require.FileExists(t, opts.PythonExe)
+
+			pythonExe, err := exec.LookPath(python.GetExecutable())
+			require.NoError(t, err)
+			require.Equal(t, filepath.Dir(pythonExe), filepath.Dir(opts.PythonExe))
+			require.FileExists(t, pythonExe)
 		})
 	}
 }
+
+func TestWrongVersion(t *testing.T) {
+	require.Error(t, CreatePythonEnv(&VenvOpts{PythonVersion: "4.0"}))
+}
+
+func TestMissingVersion(t *testing.T) {
+	require.Error(t, CreatePythonEnv(nil))
+	require.Error(t, CreatePythonEnv(&VenvOpts{}))
+}