Refactor reducer to enable testing

cmd/reduce.go

@@ -17,7 +17,6 @@ type reduceOpts struct {
 	in         []string
 	repofiles  []string
 	out        string
-	lang       string
 	nobest     bool
 	arch       string
 	baseSystem string
@@ -43,13 +42,7 @@ which allow reducing huge rpm repos to a smaller problem set for debugging, remo
 					return err
 				}
 			}
-			repo := reducer.NewRepoReducer(repos, reduceopts.in, reduceopts.lang, reduceopts.baseSystem, reduceopts.arch, ".bazeldnf")
-			logrus.Info("Loading packages.")
-			if err := repo.Load(); err != nil {
-				return err
-			}
-			logrus.Info("Reduction of involved packages.")
-			_, involved, err := repo.Resolve(required)
+			_, involved, err := reducer.Resolve(repos, reduceopts.in, reduceopts.baseSystem, reduceopts.arch, required)
 			if err != nil {
 				return err
 			}

cmd/resolve.go

@@ -14,7 +14,6 @@ import (
 
 type resolveOpts struct {
 	in               []string
-	lang             string
 	nobest           bool
 	arch             string
 	baseSystem       string
@@ -40,13 +39,7 @@ func NewResolveCmd() *cobra.Command {
 					return err
 				}
 			}
-			repo := reducer.NewRepoReducer(repos, resolveopts.in, resolveopts.lang, resolveopts.baseSystem, resolveopts.arch, ".bazeldnf")
-			logrus.Info("Loading packages.")
-			if err := repo.Load(); err != nil {
-				return err
-			}
-			logrus.Info("Initial reduction of involved packages.")
-			matched, involved, err := repo.Resolve(required)
+			matched, involved, err := reducer.Resolve(repos, resolveopts.in, resolveopts.baseSystem, resolveopts.arch, required)
 			if err != nil {
 				return err
 			}

cmd/rpmtree.go

@@ -14,7 +14,6 @@ import (
 )
 
 type rpmtreeOpts struct {
-	lang             string
 	nobest           bool
 	arch             string
 	baseSystem       string
@@ -42,13 +41,7 @@ func NewRpmTreeCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			repoReducer := reducer.NewRepoReducer(repos, nil, rpmtreeopts.lang, rpmtreeopts.baseSystem, rpmtreeopts.arch, ".bazeldnf")
-			logrus.Info("Loading packages.")
-			if err := repoReducer.Load(); err != nil {
-				return err
-			}
-			logrus.Info("Initial reduction of involved packages.")
-			matched, involved, err := repoReducer.Resolve(required)
+			matched, involved, err := reducer.Resolve(repos, nil, rpmtreeopts.baseSystem, rpmtreeopts.arch, required)
 			if err != nil {
 				return err
 			}

pkg/reducer/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "reducer",
     srcs = [
         "doc.go",
+        "loader.go",
         "reducer.go",
     ],
     importpath = "github.com/rmohr/bazeldnf/pkg/reducer",

pkg/reducer/loader.go

@@ -0,0 +1,96 @@
+package reducer
+
+import (
+	"encoding/xml"
+	"os"
+
+	"github.com/rmohr/bazeldnf/pkg/api"
+	"github.com/rmohr/bazeldnf/pkg/api/bazeldnf"
+)
+
+type RepoCache interface {
+	CurrentPrimaries(repos *bazeldnf.Repositories, arch string) (primaries []*api.Repository, err error)
+}
+
+type ReducerPackageLoader interface {
+	Load() ([]api.Package, error)
+}
+
+type RepoLoader struct {
+	repoFiles     []string
+	arch          string
+	architectures []string
+	repos         *bazeldnf.Repositories
+	cacheHelper   RepoCache
+}
+
+func (r RepoLoader) Load() ([]api.Package, error) {
+	packages := []api.Package{}
+
+	for _, rpmrepo := range r.repoFiles {
+		repoFile := &api.Repository{}
+		f, err := os.Open(rpmrepo)
+		if err != nil {
+			return packages, err
+		}
+		defer f.Close()
+		err = xml.NewDecoder(f).Decode(repoFile)
+		if err != nil {
+			return packages, err
+		}
+		for i, p := range repoFile.Packages {
+			if skip(p.Arch, r.architectures) {
+				continue
+			}
+			packages = append(packages, repoFile.Packages[i])
+		}
+	}
+
+	cachedRepos, err := r.cacheHelper.CurrentPrimaries(r.repos, r.arch)
+	if err != nil {
+		return packages, err
+	}
+	for _, rpmrepo := range cachedRepos {
+		for i, p := range rpmrepo.Packages {
+			if skip(p.Arch, r.architectures) {
+				continue
+			}
+			packages = append(packages, rpmrepo.Packages[i])
+		}
+	}
+
+	for i, _ := range packages {
+		FixPackages(&packages[i])
+	}
+
+	return packages, nil
+}
+
+// FixPackages contains hacks which should probably not have to exist
+func FixPackages(p *api.Package) {
+	// FIXME: This is not a proper modules support for python. We should properly resolve `alternative(python)` and
+	// not have to add such a hack. On the other hand this seems to have been reverted in fedora and only exists in centos stream.
+	if p.Name == "platform-python" {
+		p.Format.Provides.Entries = append(p.Format.Provides.Entries, api.Entry{
+			Name: "/usr/libexec/platform-python",
+		})
+		var requires []api.Entry
+		for _, entry := range p.Format.Requires.Entries {
+			if entry.Name != "/usr/libexec/platform-python" {
+				requires = append(requires, entry)
+			}
+		}
+		p.Format.Requires.Entries = requires
+	}
+}
+
+func skip(arch string, arches []string) bool {
+	skip := true
+	for _, a := range arches {
+		if a == arch {
+			skip = false
+			break
+		}
+	}
+	return skip
+}

pkg/reducer/reducer.go

@@ -1,9 +1,7 @@
 package reducer
 
 import (
-	"encoding/xml"
 	"fmt"
-	"os"
 	"strings"
 
 	"github.com/rmohr/bazeldnf/pkg/api"
@@ -14,50 +12,18 @@ import (
 
 type RepoReducer struct {
 	packages         []api.Package
-	lang             string
-	repoFiles        []string
 	provides         map[string][]*api.Package
 	implicitRequires []string
-	arch             string
-	architectures    []string
-	repos            *bazeldnf.Repositories
-	cacheHelper      *repo.CacheHelper
+	loader           ReducerPackageLoader
 }
 
 func (r *RepoReducer) Load() error {
-	for _, rpmrepo := range r.repoFiles {
-		repoFile := &api.Repository{}
-		f, err := os.Open(rpmrepo)
-		if err != nil {
-			return err
-		}
-		defer f.Close()
-		err = xml.NewDecoder(f).Decode(repoFile)
-		if err != nil {
-			return err
-		}
-		for i, p := range repoFile.Packages {
-			if skip(p.Arch, r.architectures) {
-				continue
-			}
-			r.packages = append(r.packages, repoFile.Packages[i])
-		}
-	}
-	repos, err := r.cacheHelper.CurrentPrimaries(r.repos, r.arch)
+	packages, err := r.loader.Load()
 	if err != nil {
 		return err
 	}
-	for _, rpmrepo := range repos {
-		for i, p := range rpmrepo.Packages {
-			if skip(p.Arch, r.architectures) {
-				continue
-			}
-			r.packages = append(r.packages, rpmrepo.Packages[i])
-		}
-	}
-	for i, _ := range r.packages {
-		FixPackages(&r.packages[i])
-	}
+
+	r.packages = packages
 
 	for i, p := range r.packages {
 		requires := []api.Entry{}
@@ -174,45 +140,27 @@ func (r *RepoReducer) requires(p *api.Package) (wants []*api.Package) {
 	return wants
 }
 
-func NewRepoReducer(repos *bazeldnf.Repositories, repoFiles []string, lang string, baseSystem string, arch string, cachDir string) *RepoReducer {
+func NewRepoReducer(repos *bazeldnf.Repositories, repoFiles []string, baseSystem string, arch string, cachDir string) *RepoReducer {
 	return &RepoReducer{
 		packages:         nil,
-		lang:             lang,
 		implicitRequires: []string{baseSystem},
-		repoFiles:        repoFiles,
 		provides:         map[string][]*api.Package{},
-		architectures:    []string{"noarch", arch},
-		arch:             arch,
-		repos:            repos,
-		cacheHelper:      &repo.CacheHelper{CacheDir: cachDir},
-	}
-}
-
-func skip(arch string, arches []string) bool {
-	skip := true
-	for _, a := range arches {
-		if a == arch {
-			skip = false
-			break
-		}
+		loader: RepoLoader{
+			repoFiles:     repoFiles,
+			architectures: []string{"noarch", arch},
+			arch:          arch,
+			repos:         repos,
+			cacheHelper:   &repo.CacheHelper{CacheDir: cachDir},
+		},
 	}
-	return skip
 }
 
-// FixPackages contains hacks which should probably not have to exist
-func FixPackages(p *api.Package) {
-	// FIXME: This is not a proper modules support for python. We should properly resolve `alternative(python)` and
-	// not have to add such a hack. On the other hand this seems to have been reverted in fedora and only exists in centos stream.
-	if p.Name == "platform-python" {
-		p.Format.Provides.Entries = append(p.Format.Provides.Entries, api.Entry{
-			Name: "/usr/libexec/platform-python",
-		})
-		var requires []api.Entry
-		for _, entry := range p.Format.Requires.Entries {
-			if entry.Name != "/usr/libexec/platform-python" {
-				requires = append(requires, entry)
-			}
-		}
-		p.Format.Requires.Entries = requires
+func Resolve(repos *bazeldnf.Repositories, repoFiles []string, baseSystem, arch string, packages []string) (matched []string, involved []*api.Package, err error) {
+	repoReducer := NewRepoReducer(repos, repoFiles, baseSystem, arch, ".bazeldnf")
+	logrus.Info("Loading packages.")
+	if err := repoReducer.Load(); err != nil {
+		return nil, nil, err
 	}
+	logrus.Info("Initial reduction of involved packages.")
+	return repoReducer.Resolve(packages)
 }