internal/find_blender/find_blender.go

@@ -53,8 +53,24 @@ func FileAssociation() (string, error) {
 }
 
 // EnvironmentVariable returns the full path of a Blender executable, by checking the environment.
-func EnvironmentVariable() string {
-	return os.Getenv(BlenderPathEnvVariable)
+func EnvironmentVariable() (string, string, error) {
+
+	// Check the environment for a full path
+	fullPath := os.Getenv(BlenderPathEnvVariable)
+	if fullPath == "" {
+		return BlenderPathEnvVariable, "", nil
+	}
+
+	// Make sure the path exists and is not a directory
+	stat, err := os.Stat(fullPath)
+	if err != nil {
+		return BlenderPathEnvVariable, fullPath, err
+	}
+	if stat.IsDir() {
+		return BlenderPathEnvVariable, fullPath, fmt.Errorf("Path from environment is a directory: %s", fullPath)
+	}
+
+	return BlenderPathEnvVariable, fullPath, nil
 }
 
 func CheckBlender(ctx context.Context, exename string) (CheckBlenderResult, error) {
@@ -66,10 +82,12 @@ func CheckBlender(ctx context.Context, exename string) (CheckBlenderResult, erro
 	}
 
 	// Check the environment for a full path
-	envFullPath := EnvironmentVariable()
+	_, envFullPath, err := EnvironmentVariable()
+	if err != nil {
+		return CheckBlenderResult{}, err
+	}
 	if envFullPath != "" {
-		// The full path was found in the environment, report the Blender version.
-		return getResultWithVersion(ctx, exename, envFullPath, api.BlenderPathSourceInputPath)
+		return getResultWithVersion(ctx, exename, envFullPath, api.BlenderPathSourceEnvVariable)
 	}
 
 	if exename == "" {

internal/find_blender/find_blender_test.go

@@ -7,6 +7,7 @@ import (
 	"flag"
 	"os"
 	"os/exec"
+	"runtime"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -45,21 +46,59 @@ func TestGetBlenderVersion(t *testing.T) {
 
 func TestGetBlenderCommandFromEnvironment(t *testing.T) {
 
-	// If the environment variable is unset or empty, we expect an empty string
+	// If the environment variable is unset, we expect an empty string
 	err := os.Unsetenv(BlenderPathEnvVariable)
 	assert.NoError(t, err, "Could not clear blender executable from environment")
-	path := EnvironmentVariable()
+	envVar, path, err := EnvironmentVariable()
+	assert.NoError(t, err)
+	assert.Equal(t, BlenderPathEnvVariable, envVar)
 	assert.Equal(t, "", path)
 
+	// If the environment variable is empty, we expect an empty string
 	err = os.Setenv(BlenderPathEnvVariable, "")
 	assert.NoError(t, err, "Could not set blender executable in environment")
-	path = EnvironmentVariable()
+	envVar, path, err = EnvironmentVariable()
+	assert.NoError(t, err)
+	assert.Equal(t, BlenderPathEnvVariable, envVar)
 	assert.Equal(t, "", path)
 
-	// Try finding the blender path in the environment variable
+	// Try finding a non-existing executable in the environment variable
 	envExe := `D:\Blender_3.2_stable\blender.exe`
 	err = os.Setenv(BlenderPathEnvVariable, envExe)
 	assert.NoError(t, err, "Could not set blender executable in environment")
-	path = EnvironmentVariable()
-	assert.Equal(t, envExe, path)
+	envVar, path, err = EnvironmentVariable()
+	assert.Error(t, err)
+	assert.Equal(t, path, envExe)
+	assert.Equal(t, BlenderPathEnvVariable, envVar)
+
+	// Try finding a existing file in the environment variable
+	// We use this filename instead of a real blender executable
+	_, myFilename, _, _ := runtime.Caller(0)
+	err = os.Setenv(BlenderPathEnvVariable, myFilename)
+	assert.NoError(t, err, "Could not set blender executable in environment")
+	envVar, path, err = EnvironmentVariable()
+	assert.NoError(t, err)
+	assert.Equal(t, path, myFilename)
+	assert.Equal(t, BlenderPathEnvVariable, envVar)
+
+	if !*withBlender {
+		t.Skip("skipping test, -withBlender arg not passed")
+	}
+
+	existingPath, err := exec.LookPath("blender")
+	if err != nil {
+		existingPath, err = fileAssociation()
+		if !assert.NoError(t, err) {
+			t.Fatal("running with -withBlender requires having a `blender` command on $PATH or a file association to .blend files")
+		}
+	}
+
+	// Try finding an existing executable in the environment variable
+	err = os.Setenv(BlenderPathEnvVariable, existingPath)
+	assert.NoError(t, err, "Could not set blender executable in environment")
+	envVar, path, err = EnvironmentVariable()
+	assert.NoError(t, err)
+	assert.Equal(t, path, existingPath)
+	assert.Equal(t, BlenderPathEnvVariable, envVar)
+
 }

internal/worker/command_blender.go

@@ -88,10 +88,14 @@ func (ce *CommandExecutor) cmdBlenderRenderCommand(
 	if crosspath.Dir(parameters.exe) == "." {
 		// No directory path given. Check that the executable is set in an
 		// environment variable or can be found on the path.
-		if path := find_blender.EnvironmentVariable(); path != "" {
-			msg := fmt.Sprintf("using blender from %s", find_blender.BlenderPathEnvVariable)
-			logger.Info().Str("path", path).Msg(msg)
-			parameters.exe = path
+		envVar, envPath, err := find_blender.EnvironmentVariable()
+		if err != nil {
+			return nil, err
+		}
+		if envPath != "" {
+			msg := fmt.Sprintf("using blender from %s", envVar)
+			logger.Info().Str("path", envPath).Msg(msg)
+			parameters.exe = envPath
 		} else if _, err := exec.LookPath(parameters.exe); err != nil {
 			// Attempt a platform-specific way to find which Blender executable to
 			// use. If Blender cannot not be found, just use the configured command

internal/worker/command_blender_test.go

@@ -3,6 +3,7 @@ package worker
 import (
 	"context"
 	"os"
+	"runtime"
 	"testing"
 
 	"github.com/golang/mock/gomock"
@@ -87,7 +88,10 @@ func TestCmdBlenderFromEnvironment(t *testing.T) {
 
 	ce, mocks := testCommandExecutor(t, mockCtrl)
 
-	envExe := `D:\Blender_3.2_stable\blender.exe`
+	// We pass this file as blender executable because it must exist
+	// envExe := `D:\Blender_3.2_stable\blender.exe`
+	_, myFilename, _, _ := runtime.Caller(0)
+	envExe := myFilename
 
 	err := os.Setenv(find_blender.BlenderPathEnvVariable, envExe)
 	assert.NoError(t, err, "Could not set blender executable in environment")