Use values in relationship To/From fields (#2871)

* use pkg values in relationship fields

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* add linter rule for using values in relationships

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* use new cmptest package for comparing relationships

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* create cmptest for common cmp.Diff options in test

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* condense matches for relationship ruleguard

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* remove relationship type from rules

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* restore build tag

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* suggest using values

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* nil check pkgs

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

internal/cmptest/common_options.go

@@ -0,0 +1,71 @@
+package cmptest
+
+import (
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+
+	"github.com/anchore/syft/syft/file"
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func DefaultCommonOptions() []cmp.Option {
+	return CommonOptions(nil, nil)
+}
+
+func CommonOptions(licenseCmp LicenseComparer, locationCmp LocationComparer) []cmp.Option {
+	if licenseCmp == nil {
+		licenseCmp = DefaultLicenseComparer
+	}
+
+	if locationCmp == nil {
+		locationCmp = DefaultLocationComparer
+	}
+
+	return []cmp.Option{
+		cmpopts.IgnoreFields(pkg.Package{}, "id"), // note: ID is not deterministic for test purposes
+		cmpopts.SortSlices(pkg.Less),
+		cmpopts.SortSlices(DefaultRelationshipComparer),
+		cmp.Comparer(
+			func(x, y file.LocationSet) bool {
+				xs := x.ToSlice()
+				ys := y.ToSlice()
+
+				if len(xs) != len(ys) {
+					return false
+				}
+				for i, xe := range xs {
+					ye := ys[i]
+					if !locationCmp(xe, ye) {
+						return false
+					}
+				}
+
+				return true
+			},
+		),
+		cmp.Comparer(
+			func(x, y pkg.LicenseSet) bool {
+				xs := x.ToSlice()
+				ys := y.ToSlice()
+
+				if len(xs) != len(ys) {
+					return false
+				}
+				for i, xe := range xs {
+					ye := ys[i]
+					if !licenseCmp(xe, ye) {
+						return false
+					}
+				}
+
+				return true
+			},
+		),
+		cmp.Comparer(
+			locationCmp,
+		),
+		cmp.Comparer(
+			licenseCmp,
+		),
+	}
+}

internal/cmptest/diff_reporter.go

@@ -0,0 +1,37 @@
+package cmptest
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+// DiffReporter is a simple custom reporter that only records differences detected during comparison.
+type DiffReporter struct {
+	path  cmp.Path
+	diffs []string
+}
+
+func NewDiffReporter() DiffReporter {
+	return DiffReporter{}
+}
+
+func (r *DiffReporter) PushStep(ps cmp.PathStep) {
+	r.path = append(r.path, ps)
+}
+
+func (r *DiffReporter) Report(rs cmp.Result) {
+	if !rs.Equal() {
+		vx, vy := r.path.Last().Values()
+		r.diffs = append(r.diffs, fmt.Sprintf("%#v:\n\t-: %+v\n\t+: %+v\n", r.path, vx, vy))
+	}
+}
+
+func (r *DiffReporter) PopStep() {
+	r.path = r.path[:len(r.path)-1]
+}
+
+func (r *DiffReporter) String() string {
+	return strings.Join(r.diffs, "\n")
+}

internal/cmptest/license.go

@@ -0,0 +1,29 @@
+package cmptest
+
+import (
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/anchore/syft/syft/file"
+	"github.com/anchore/syft/syft/pkg"
+)
+
+type LicenseComparer func(x, y pkg.License) bool
+
+func DefaultLicenseComparer(x, y pkg.License) bool {
+	return cmp.Equal(x, y, cmp.Comparer(DefaultLocationComparer), cmp.Comparer(
+		func(x, y file.LocationSet) bool {
+			xs := x.ToSlice()
+			ys := y.ToSlice()
+			if len(xs) != len(ys) {
+				return false
+			}
+			for i, xe := range xs {
+				ye := ys[i]
+				if !DefaultLocationComparer(xe, ye) {
+					return false
+				}
+			}
+			return true
+		},
+	))
+}

internal/cmptest/location.go

@@ -0,0 +1,13 @@
+package cmptest
+
+import (
+	"github.com/google/go-cmp/cmp"
+
+	"github.com/anchore/syft/syft/file"
+)
+
+type LocationComparer func(x, y file.Location) bool
+
+func DefaultLocationComparer(x, y file.Location) bool {
+	return cmp.Equal(x.Coordinates, y.Coordinates) && cmp.Equal(x.AccessPath, y.AccessPath)
+}

internal/cmptest/relationship.go

@@ -0,0 +1,26 @@
+package cmptest
+
+import (
+	"github.com/sanity-io/litter"
+
+	"github.com/anchore/syft/syft/artifact"
+)
+
+type RelationshipComparer func(x, y artifact.Relationship) bool
+
+var relationshipStringer = litter.Options{
+	Compact:           true,
+	StripPackageNames: false,
+	HidePrivateFields: true, // we want to ignore package IDs
+	HideZeroValues:    true,
+	StrictGo:          true,
+	//FieldExclusions: ...  // these can be added for future values that need to be ignored
+	//FieldFilter: ...
+}
+
+func DefaultRelationshipComparer(x, y artifact.Relationship) bool {
+	// we just need a stable sort, the ordering does not need to be sensible
+	xStr := relationshipStringer.Sdump(x)
+	yStr := relationshipStringer.Sdump(y)
+	return xStr < yStr
+}