🎁 Allow to override version via environmental variables to be used on CI (#22)

* Introducing version.Resolver type for compatibility with #20

* Impementing knative style version resolver using composite, ordered, and git resolvers.

* Adding additional tests and fixes

* More tests to pinpoint the failure

* Knative version resolver work properly

* Lint fix

Author: cardil

pkg/cache/noop.go

@@ -0,0 +1,13 @@
+package cache
+
+// NoopCache do not do any caching. Probably, should be only used for testing
+// purposes.
+type NoopCache struct{}
+
+func (n NoopCache) Compute(_ interface{}, provider func() (interface{}, error)) (interface{}, error) {
+	return provider()
+}
+
+func (n NoopCache) Drop(_ interface{}) interface{} {
+	return nil
+}

pkg/environment/types.go

@@ -0,0 +1,56 @@
+package environment
+
+import (
+	"os"
+	"strings"
+)
+
+// Key is an environment key.
+type Key string
+
+// Value is an environment value.
+type Value string
+
+// Pair holds a pair of environment key and value.
+type Pair struct {
+	Key
+	Value
+}
+
+// Values holds environment values together with their keys.
+type Values map[Key]Value
+
+// ValuesSupplier is a func that supplies environmental values.
+type ValuesSupplier func() Values
+
+// Add a pair to environment values.
+func (v Values) Add(pair Pair) {
+	v[pair.Key] = pair.Value
+}
+
+// New returns an environmental values bases on input compatible with the
+// os.Environ function.
+func New(environ ...string) Values {
+	vals := Values(map[Key]Value{})
+	for _, pair := range environ {
+		vals.Add(NewPair(pair))
+	}
+	return vals
+}
+
+// Current returns current environment values, from os.Environ method.
+func Current() Values {
+	return New(os.Environ()...)
+}
+
+// NewPair creates a pair from os.Environ style string.
+func NewPair(environ string) Pair {
+	parts := strings.SplitN(environ, "=", pairElements)
+	pair := Pair{Key: Key(parts[0])}
+	if len(parts) > 1 {
+		pair.Value = Value(parts[1])
+	}
+	return pair
+}
+
+const pairElements = 2

pkg/environment/types_test.go

@@ -0,0 +1,14 @@
+package environment_test
+
+import (
+	"testing"
+
+	"github.com/wavesoftware/go-magetasks/pkg/environment"
+	"gotest.tools/v3/assert"
+)
+
+func TestNew(t *testing.T) {
+	e := environment.New("TAG=v4.5.6", "PUSH_RELEASE=1")
+	assert.Equal(t, e[environment.Key("TAG")], environment.Value("v4.5.6"))
+	assert.Equal(t, e[environment.Key("PUSH_RELEASE")], environment.Value("1"))
+}

pkg/environment/version.go

@@ -0,0 +1,81 @@
+package environment
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrNotSupported when operation is not supported.
+var ErrNotSupported = errors.New("not supported")
+
+// NewVersionResolver creates a VersionResolver using options.
+func NewVersionResolver(options ...VersionResolverOption) VersionResolver {
+	r := VersionResolver{}
+
+	for _, option := range options {
+		option(&r)
+	}
+
+	return r
+}
+
+// WithValuesSupplier allows to set the values supplier.
+func WithValuesSupplier(vs ValuesSupplier) VersionResolverOption {
+	return func(r *VersionResolver) {
+		r.ValuesSupplier = vs
+	}
+}
+
+// VersionResolverOption is used to customize creation of VersionResolver.
+type VersionResolverOption func(*VersionResolver)
+
+// VersionResolver is used to resolve version information solely on
+// environment variables.
+type VersionResolver struct {
+	VersionKey   Key
+	IsApplicable []Check
+	ValuesSupplier
+}
+
+// Check is used to verify environment values.
+type Check Pair
+
+func (e VersionResolver) Version() string {
+	values := e.environment()
+	if !e.isApplicable(values) {
+		return ""
+	}
+	return string(values[e.VersionKey])
+}
+
+func (e VersionResolver) IsLatest(versionRange string) (bool, error) {
+	return false, fmt.Errorf(
+		"%w: IsLatest(versionRange string) by environment.VersionResolver",
+		ErrNotSupported)
+}
+
+func (e VersionResolver) environment() Values {
+	supplier := Current
+	if e.ValuesSupplier != nil {
+		supplier = e.ValuesSupplier
+	}
+	return supplier()
+}
+
+func (e VersionResolver) isApplicable(values Values) bool {
+	for _, check := range e.IsApplicable {
+		if !check.test(values) {
+			return false
+		}
+	}
+	return true
+}
+
+func (c Check) test(values Values) bool {
+	if c.Value == "" {
+		_, ok := values[c.Key]
+		return ok
+	}
+	val, ok := values[c.Key]
+	return ok && val == c.Value
+}

pkg/environment/version_test.go

@@ -0,0 +1,49 @@
+package environment_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/wavesoftware/go-magetasks/pkg/environment"
+	"github.com/wavesoftware/go-magetasks/pkg/testing/errors"
+	"github.com/wavesoftware/go-magetasks/pkg/version"
+	"gotest.tools/v3/assert"
+)
+
+func TestVersionResolver(t *testing.T) {
+	tests := []testCase{{
+		environment: environment.New(),
+	}, {
+		environment: environment.New("TAG=v4.6.23", "TAG_RELEASE=1"),
+		version:     "v4.6.23",
+	}, {
+		environment: environment.New("TAG=v6.23.0", "TAG_RELEASE=1", "is_auto_release=1"),
+		version:     "v6.23.0",
+	}}
+	for i, tc := range tests {
+		tc := tc
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			resolver := tc.resolver()
+			assert.Equal(t, resolver.Version(), tc.version)
+			_, err := resolver.IsLatest(version.AnyVersion)
+			errors.Check(t, err, environment.ErrNotSupported)
+		})
+	}
+}
+
+type testCase struct {
+	environment environment.Values
+	version     string
+}
+
+func (tc testCase) resolver() version.Resolver {
+	return environment.VersionResolver{
+		VersionKey: "TAG",
+		IsApplicable: []environment.Check{{
+			Key: "TAG_RELEASE", Value: "1",
+		}},
+		ValuesSupplier: func() environment.Values {
+			return tc.environment
+		},
+	}
+}

pkg/git/resolver.go

@@ -1,82 +1,104 @@
 package git
 
 import (
-	"errors"
-
 	"github.com/wavesoftware/go-ensure"
 	"github.com/wavesoftware/go-magetasks/config"
 	"github.com/wavesoftware/go-magetasks/pkg/cache"
 	"github.com/wavesoftware/go-magetasks/pkg/version"
 )
 
-// IsLatestStrategy is used to determine if current version is latest one.
-type IsLatestStrategy func(Resolver) func(versionRange string) (bool, error)
+type VersionResolverOption func(*VersionResolver)
 
-// Remote represents a remote repository name and address.
-type Remote struct {
-	Name string
-	URL  string
+func NewVersionResolver(options ...VersionResolverOption) VersionResolver {
+	r := VersionResolver{}
+
+	for _, option := range options {
+		option(&r)
+	}
+
+	return r
+}
+
+func WithCache(cache cache.Cache) VersionResolverOption {
+	return func(r *VersionResolver) {
+		r.Cache = cache
+	}
 }
 
-// Resolver implements version.Resolver for git SCM.
-type Resolver struct {
+func WithIsLatestStrategy(strategy IsLatestStrategy) VersionResolverOption {
+	return func(r *VersionResolver) {
+		r.IsLatestStrategy = strategy
+	}
+}
+
+func WithRepository(repository Repository) VersionResolverOption {
+	return func(r *VersionResolver) {
+		r.Repository = repository
+	}
+}
+
+func WithRemote(remote Remote) VersionResolverOption {
+	return func(r *VersionResolver) {
+		r.Remote = &remote
+	}
+}
+
+// VersionResolver implements version.Resolver for git SCM.
+type VersionResolver struct {
 	Cache cache.Cache
 	IsLatestStrategy
 	Repository
 	*Remote
 }
 
+// Remote represents a remote repository name and address.
+type Remote struct {
+	Name string
+	URL  string
+}
+
+// IsLatestStrategy is used to determine if current version is latest one.
+type IsLatestStrategy func(version.Resolver) func(string) (bool, error)
+
 type cacheKey struct {
 	typee string
 }
 
-func (r Resolver) Version() string {
+func (r VersionResolver) Version() string {
 	ver, err := r.cache().Compute(cacheKey{"version"}, func() (interface{}, error) {
 		return r.repository().Describe()
 	})
 	ensure.NoError(err)
 	return ver.(string)
 }
 
-func (r Resolver) IsLatest(versionRange string) (bool, error) {
-	strategy := TagBasedIsLatestStrategy
-	if r.IsLatestStrategy != nil {
-		strategy = r.IsLatestStrategy
-	}
-	fn := strategy(r)
-	latest, err := fn(versionRange)
-	if err != nil {
-		if !errors.Is(err, version.ErrVersionIsNotValid) {
-			return false, err
-		}
-		return false, nil
-	}
-	return latest, nil
+func (r VersionResolver) IsLatest(versionRange string) (bool, error) {
+	return ResolveIsLatest(r, r, versionRange)
 }
 
-func (r Resolver) cache() cache.Cache {
+func (r VersionResolver) cache() cache.Cache {
 	if r.Cache == nil {
 		return config.Cache()
 	}
 	return r.Cache
 }
 
-func (r Resolver) repository() Repository {
+func (r VersionResolver) repository() Repository {
 	if r.Repository == nil {
 		return installedGitBinaryRepo{r.remote()}
 	}
 	return r.Repository
 }
 
-func (r Resolver) remote() Remote {
+func (r VersionResolver) remote() Remote {
 	remote := Remote{Name: "origin"}
 	if r.Remote != nil {
 		remote = *r.Remote
 	}
 	return remote
 }
 
-func (r Resolver) resolveTags() []string {
+func (r VersionResolver) resolveTags() []string {
 	tt, err := r.cache().Compute(cacheKey{"tags"}, func() (interface{}, error) {
 		return r.repository().Tags()
 	})