diff --git a/cmpserver/plugin/plugin.go b/cmpserver/plugin/plugin.go
index 3990b0fa2796d..909d420acb371 100644
--- a/cmpserver/plugin/plugin.go
+++ b/cmpserver/plugin/plugin.go
@@ -46,8 +46,7 @@ func NewService(initConstants CMPServerInitConstants) *Service {
 	}
 }
 
-func (s *Service) Init() error {
-	workDir := common.GetCMPWorkDir()
+func (s *Service) Init(workDir string) error {
 	err := os.RemoveAll(workDir)
 	if err != nil {
 		return fmt.Errorf("error removing workdir %q: %s", workDir, err)
diff --git a/cmpserver/plugin/plugin_test.go b/cmpserver/plugin/plugin_test.go
index b3940aa0256ec..c796cb8c80e86 100644
--- a/cmpserver/plugin/plugin_test.go
+++ b/cmpserver/plugin/plugin_test.go
@@ -3,6 +3,7 @@ package plugin
 import (
 	"context"
 	"os"
+	"path"
 	"path/filepath"
 	"testing"
 	"time"
@@ -12,6 +13,7 @@ import (
 	"gopkg.in/yaml.v2"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 
+	"github.com/argoproj/argo-cd/v2/cmpserver/apiclient"
 	repoclient "github.com/argoproj/argo-cd/v2/reposerver/apiclient"
 	"github.com/argoproj/argo-cd/v2/test"
 )
@@ -32,6 +34,11 @@ func newService(configFilePath string) (*Service, error) {
 	return service, nil
 }
 
+func (s *Service) WithGenerateCommand(command Command) *Service {
+	s.initConstants.PluginConfig.Spec.Generate = command
+	return s
+}
+
 type pluginOpt func(*CMPServerInitConstants)
 
 func withDiscover(d Discover) pluginOpt {
@@ -104,6 +111,19 @@ func TestMatchRepository(t *testing.T) {
 		assert.NoError(t, err)
 		assert.False(t, match)
 	})
+	t.Run("will not match a pattern with a syntax error", func(t *testing.T) {
+		// given
+		d := Discover{
+			FileName: "[",
+		}
+		f := setup(t, withDiscover(d))
+
+		// when
+		_, err := f.service.matchRepository(context.Background(), f.path)
+
+		// then
+		assert.ErrorContains(t, err, "syntax error")
+	})
 	t.Run("will match plugin by glob", func(t *testing.T) {
 		// given
 		d := Discover{
@@ -136,6 +156,21 @@ func TestMatchRepository(t *testing.T) {
 		assert.NoError(t, err)
 		assert.False(t, match)
 	})
+	t.Run("will throw an error for a bad pattern", func(t *testing.T) {
+		// given
+		d := Discover{
+			Find: Find{
+				Glob: "does-not-exist",
+			},
+		}
+		f := setup(t, withDiscover(d))
+
+		// when
+		_, err := f.service.matchRepository(context.Background(), f.path)
+
+		// then
+		assert.ErrorContains(t, err, "error finding glob match for pattern")
+	})
 	t.Run("will match plugin by command when returns any output", func(t *testing.T) {
 		// given
 		d := Discover{
@@ -201,17 +236,49 @@ func Test_Negative_ConfigFile_DoesnotExist(t *testing.T) {
 
 func TestGenerateManifest(t *testing.T) {
 	configFilePath := "./testdata/kustomize/config"
-	service, err := newService(configFilePath)
-	require.NoError(t, err)
 
-	res1, err := service.generateManifest(context.Background(), "", nil)
+	t.Run("successful generate", func(t *testing.T) {
+		service, err := newService(configFilePath)
+		require.NoError(t, err)
+
+		res1, err := service.generateManifest(context.Background(), "", nil)
+		require.NoError(t, err)
+		require.NotNil(t, res1)
+
+		expectedOutput := "{\"apiVersion\":\"v1\",\"data\":{\"foo\":\"bar\"},\"kind\":\"ConfigMap\",\"metadata\":{\"name\":\"my-map\"}}"
+		if res1 != nil {
+			require.Equal(t, expectedOutput, res1.Manifests[0])
+		}
+	})
+	t.Run("bad generate command", func(t *testing.T) {
+		service, err := newService(configFilePath)
+		require.NoError(t, err)
+		service.WithGenerateCommand(Command{Command: []string{"bad-command"}})
+
+		res, err := service.generateManifest(context.Background(), "", nil)
+		assert.ErrorContains(t, err, "executable file not found")
+		assert.Nil(t, res.Manifests)
+	})
+	t.Run("bad yaml output", func(t *testing.T) {
+		service, err := newService(configFilePath)
+		require.NoError(t, err)
+		service.WithGenerateCommand(Command{Command: []string{"echo", "invalid yaml: }"}})
+
+		res, err := service.generateManifest(context.Background(), "", nil)
+		assert.ErrorContains(t, err, "failed to unmarshal manifest")
+		assert.Nil(t, res.Manifests)
+	})
+}
+
+func TestGenerateManifest_deadline_exceeded(t *testing.T) {
+	configFilePath := "./testdata/kustomize/config"
+	service, err := newService(configFilePath)
 	require.NoError(t, err)
-	require.NotNil(t, res1)
 
-	expectedOutput := "{\"apiVersion\":\"v1\",\"data\":{\"foo\":\"bar\"},\"kind\":\"ConfigMap\",\"metadata\":{\"name\":\"my-map\"}}"
-	if res1 != nil {
-		require.Equal(t, expectedOutput, res1.Manifests[0])
-	}
+	expiredCtx, cancel := context.WithTimeout(context.Background(), time.Second * 0)
+	defer cancel()
+	_, err = service.generateManifest(expiredCtx, "", nil)
+	assert.ErrorContains(t, err, "context deadline exceeded")
 }
 
 // TestRunCommandContextTimeout makes sure the command dies at timeout rather than sleeping past the timeout.
@@ -230,6 +297,11 @@ func TestRunCommandContextTimeout(t *testing.T) {
 	assert.Less(t, after.Sub(before), 1*time.Second)
 }
 
+func TestRunCommandEmptyCommand(t *testing.T) {
+	_, err := runCommand(context.Background(), Command{}, "", nil)
+	assert.ErrorContains(t, err, "Command is empty")
+}
+
 func Test_getParametersAnnouncement_empty_command(t *testing.T) {
 	staticYAML := `
 - name: static-a
@@ -306,6 +378,15 @@ func Test_getParametersAnnouncement_bad_command(t *testing.T) {
 
 func Test_getTempDirMustCleanup(t *testing.T) {
 	tempDir := t.TempDir()
+
+	// Induce a directory create error to verify error handling.
+	err := os.Chmod(tempDir, 0000)
+	require.NoError(t, err)
+	_, _, err = getTempDirMustCleanup(path.Join(tempDir, "test"))
+	assert.ErrorContains(t, err, "error creating temp dir")
+
+	err = os.Chmod(tempDir, 0700)
+	require.NoError(t, err)
 	workDir, cleanup, err := getTempDirMustCleanup(tempDir)
 	require.NoError(t, err)
 	require.DirExists(t, workDir)
@@ -322,3 +403,52 @@ func Test_getTempDirMustCleanup(t *testing.T) {
 	cleanup()
 	assert.NoDirExists(t, workDir)
 }
+
+func TestService_Init(t *testing.T) {
+	// Set up a base directory containing a test directory and a test file.
+	tempDir := t.TempDir()
+	workDir := path.Join(tempDir, "workDir")
+	err := os.MkdirAll(workDir, 0700)
+	require.NoError(t, err)
+	testfile := path.Join(workDir, "testfile")
+	file, err := os.Create(testfile)
+	require.NoError(t, err)
+	err = file.Close()
+	require.NoError(t, err)
+
+	// Make the base directory read-only so Init's cleanup fails.
+	err = os.Chmod(tempDir, 0000)
+	require.NoError(t, err)
+	s := NewService(CMPServerInitConstants{PluginConfig: PluginConfig{}})
+	err = s.Init(workDir)
+	assert.ErrorContains(t, err, "error removing workdir", "Init must throw an error if it can't remove the work directory")
+
+	// Make the base directory writable so Init's cleanup succeeds.
+	err = os.Chmod(tempDir, 0700)
+	require.NoError(t, err)
+	err = s.Init(workDir)
+	assert.NoError(t, err)
+	assert.DirExists(t, workDir)
+	assert.NoFileExists(t, testfile)
+}
+
+func TestEnviron(t *testing.T) {
+	t.Run("empty environ", func(t *testing.T) {
+		env := environ([]*apiclient.EnvEntry{})
+		assert.Nil(t, env)
+	})
+	t.Run("env vars with empty names or values", func(t *testing.T) {
+		env := environ([]*apiclient.EnvEntry{
+			{Value: "test"},
+			{Name: "test"},
+		})
+		assert.Nil(t, env)
+	})
+	t.Run("proper env vars", func(t *testing.T) {
+		env := environ([]*apiclient.EnvEntry{
+			{Name: "name1", Value: "value1"},
+			{Name: "name2", Value: "value2"},
+		})
+		assert.Equal(t, []string{"name1=value1", "name2=value2"}, env)
+	})
+}
diff --git a/cmpserver/server.go b/cmpserver/server.go
index 636dbcd1f7339..635f8771b4f78 100644
--- a/cmpserver/server.go
+++ b/cmpserver/server.go
@@ -2,12 +2,13 @@ package cmpserver
 
 import (
 	"fmt"
-	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 	"net"
 	"os"
 	"os/signal"
 	"syscall"
 
+	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
+
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	grpc_logrus "github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus"
 	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
@@ -101,7 +102,7 @@ func (a *ArgoCDCMPServer) CreateGRPC() (*grpc.Server, error) {
 		return true, nil
 	}))
 	pluginService := plugin.NewService(a.initConstants)
-	err := pluginService.Init()
+	err := pluginService.Init(common.GetCMPWorkDir())
 	if err != nil {
 		return nil, fmt.Errorf("error initializing plugin service: %s", err)
 	}