Test Local Driver (#145)

Add unit tests for local driver. Increases code coverage for the driver by 18%.

* Test local driver

Signed-off-by: Will Beason <willbeason@google.com>

* Continue testing local driver

Signed-off-by: Will Beason <willbeason@google.com>

* Finish Local Driver unit tests

Signed-off-by: Will Beason <willbeason@google.com>

* Revert unintentional changes

Signed-off-by: Will Beason <willbeason@google.com>

* Register external_data builtin

Signed-off-by: Will Beason <willbeason@google.com>

* Continue reverting unintentional changes

Signed-off-by: Will Beason <willbeason@google.com>

* Minor refactorings

Signed-off-by: Will Beason <willbeason@google.com>

* Make arg names consistent

Signed-off-by: Will Beason <willbeason@google.com>

* Resolve nits

Signed-off-by: Will Beason <willbeason@google.com>

* Re-add tracing

Signed-off-by: Will Beason <willbeason@google.com>

* Resolve merge conflicts

Signed-off-by: Will Beason <willbeason@google.com>

* Continue resolving merge conflicts

Signed-off-by: Will Beason <willbeason@google.com>

constraint/go.mod

@@ -16,7 +16,7 @@ require (
 	github.com/mitchellh/mapstructure v1.4.1 // indirect
 	github.com/onsi/gomega v1.10.5
 	github.com/open-policy-agent/opa v0.29.4
-	github.com/pkg/errors v0.9.1
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.10.0 // indirect
 	github.com/prometheus/common v0.25.0 // indirect
 	github.com/rcrowley/go-metrics v0.0.0-20201227073835-cf1acfcdf475 // indirect

constraint/pkg/client/backend.go

@@ -48,36 +48,43 @@ func (b *Backend) NewClient(opts ...Opt) (*Client, error) {
 	if b.hasClient {
 		return nil, errors.New("currently only one client per backend is supported")
 	}
+
 	var fields []string
 	for k := range validDataFields {
 		fields = append(fields, k)
 	}
+
 	c := &Client{
 		backend:           b,
 		constraints:       make(map[schema.GroupKind]map[string]*unstructured.Unstructured),
 		templates:         make(map[templateKey]*templateEntry),
 		allowedDataFields: fields,
 	}
+
 	var errs Errors
 	for _, opt := range opts {
 		if err := opt(c); err != nil {
 			errs = append(errs, err)
 		}
 	}
+	if len(errs) > 0 {
+		return nil, errs
+	}
+
 	for _, field := range c.allowedDataFields {
 		if !validDataFields[field] {
 			return nil, fmt.Errorf("invalid data field %s", field)
 		}
 	}
-	if len(errs) > 0 {
-		return nil, errs
-	}
+
 	if len(c.targets) == 0 {
 		return nil, errors.New("no targets registered: please register a target via client.Targets()")
 	}
+
 	if err := b.driver.Init(context.Background()); err != nil {
 		return nil, err
 	}
+
 	if err := c.init(); err != nil {
 		return nil, err
 	}

constraint/pkg/client/drivers/local/args.go

@@ -0,0 +1,87 @@
+package local
+
+import (
+	"github.com/open-policy-agent/frameworks/constraint/pkg/externaldata"
+	"github.com/open-policy-agent/opa/ast"
+	"github.com/open-policy-agent/opa/storage"
+	"github.com/open-policy-agent/opa/storage/inmem"
+	opatypes "github.com/open-policy-agent/opa/types"
+)
+
+type Arg func(*driver)
+
+func Defaults() Arg {
+	return func(d *driver) {
+		if d.compiler == nil {
+			d.compiler = ast.NewCompiler()
+		}
+
+		if d.modules == nil {
+			d.modules = make(map[string]*ast.Module)
+		}
+
+		if d.storage == nil {
+			d.storage = inmem.New()
+		}
+
+		if d.capabilities == nil {
+			d.capabilities = ast.CapabilitiesForThisVersion()
+		}
+
+		// adding external_data builtin otherwise capabilities get overridden
+		// if a capability, like http.send, is disabled
+		if d.providerCache != nil {
+			d.capabilities.Builtins = append(d.capabilities.Builtins, &ast.Builtin{
+				Name: "external_data",
+				Decl: opatypes.NewFunction(opatypes.Args(opatypes.A), opatypes.A),
+			})
+		}
+	}
+}
+
+func Tracing(enabled bool) Arg {
+	return func(d *driver) {
+		d.traceEnabled = enabled
+	}
+}
+
+func Modules(modules map[string]*ast.Module) Arg {
+	return func(d *driver) {
+		d.modules = modules
+	}
+}
+
+func Storage(s storage.Store) Arg {
+	return func(d *driver) {
+		d.storage = s
+	}
+}
+
+func AddExternalDataProviderCache(providerCache *externaldata.ProviderCache) Arg {
+	return func(d *driver) {
+		d.providerCache = providerCache
+	}
+}
+
+func DisableBuiltins(builtins ...string) Arg {
+	return func(d *driver) {
+		if d.capabilities == nil {
+			d.capabilities = ast.CapabilitiesForThisVersion()
+		}
+
+		disableBuiltins := make(map[string]bool)
+		for _, b := range builtins {
+			disableBuiltins[b] = true
+		}
+
+		var nb []*ast.Builtin
+		builtins := d.capabilities.Builtins
+		for i, b := range builtins {
+			if !disableBuiltins[b.Name] {
+				nb = append(nb, builtins[i])
+			}
+		}
+
+		d.capabilities.Builtins = nb
+	}
+}

constraint/pkg/client/drivers/local/errors.go

@@ -0,0 +1,15 @@
+package local
+
+import "errors"
+
+var (
+	ErrModuleName   = errors.New("invalid module name")
+	ErrParse        = errors.New("unable to parse module")
+	ErrCompile      = errors.New("unable to compile modules")
+	ErrModulePrefix = errors.New("invalid module prefix")
+	ErrPathInvalid  = errors.New("invalid data path")
+	ErrPathConflict = errors.New("conflicting path")
+	ErrWrite        = errors.New("error writing data")
+	ErrRead         = errors.New("error reading data")
+	ErrTransaction  = errors.New("error committing data")
+)