feat: add source of dependency error (#2720)

* feat: add source of dependency error

* add test for deps

* present the chain upwards

---------

Co-authored-by: Jo Garnier <git@jguer.space>

pkg/dep/dep_graph.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"strconv"
+	"strings"
 
 	aurc "github.com/Jguer/aur"
 	alpm "github.com/Jguer/go-alpm/v2"
@@ -474,6 +475,8 @@ func (g *Grapher) GraphFromAUR(ctx context.Context,
 
 // Removes found deps from the deps mapset and returns the found deps.
 func (g *Grapher) findDepsFromAUR(ctx context.Context,
+	graph *topo.Graph[string, *InstallInfo],
+	parentPkgName string,
 	deps mapset.Set[string],
 ) []aurc.Pkg {
 	pkgsToAdd := make([]aurc.Pkg, 0, deps.Cardinality())
@@ -541,7 +544,24 @@ func (g *Grapher) findDepsFromAUR(ctx context.Context,
 		aurPkgs = satisfyingPkgs
 
 		if len(aurPkgs) == 0 {
-			g.logger.Errorln(gotext.Get("No AUR package found for"), " ", depString)
+			// set of packages that require this dependency
+			requiredBySet := mapset.NewThreadUnsafeSet[string]()
+
+			// add current parent
+			requiredBySet.Add(parentPkgName)
+
+			// if dependency is already in graph, get all packages that require it
+			if graph.Exists(depName) {
+				if deps := graph.Dependents(depName); deps != nil {
+					for parent := range deps {
+						requiredBySet.Add(parent)
+					}
+				}
+			}
+
+			requiredBySlice := requiredBySet.ToSlice()
+			requiredByStr := strings.Join(requiredBySlice, ", ")
+			g.logger.Errorln(gotext.Get("No AUR package found for"), " ", depString, " (", gotext.Get("required by"), ": ", requiredByStr, ")")
 
 			continue
 		}
@@ -671,7 +691,7 @@ func (g *Grapher) addNodes(
 	}
 
 	// Check AUR
-	pkgsToAdd := g.findDepsFromAUR(ctx, targetsToFind)
+	pkgsToAdd := g.findDepsFromAUR(ctx, graph, parentPkgName, targetsToFind)
 	for i := range pkgsToAdd {
 		aurPkg := &pkgsToAdd[i]
 		if err := graph.DependOn(aurPkg.Name, parentPkgName); err != nil {

pkg/dep/dep_graph_test.go

@@ -4,15 +4,18 @@
 package dep
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
 	"io"
 	"os"
+	"strings"
 	"testing"
 
 	aurc "github.com/Jguer/aur"
 	alpm "github.com/Jguer/go-alpm/v2"
+	mapset "github.com/deckarep/golang-set/v2"
 	"github.com/stretchr/testify/require"
 
 	"github.com/Jguer/yay/v12/pkg/db"
@@ -42,6 +45,31 @@ func getFromFile(t *testing.T, filePath string) mockaur.GetFunc {
 	}
 }
 
+func TestGrapher_findDepsFromAUR_logsRequiredByForMissingDep(t *testing.T) {
+	mockDB := &mock.DBExecutor{}
+	mockAUR := &mockaur.MockAUR{GetFn: func(ctx context.Context, query *aurc.Query) ([]aur.Pkg, error) {
+		// Simulate "no AUR package found" for any query.
+		return []aur.Pkg{}, nil
+	}}
+
+	var stderr bytes.Buffer
+	logger := text.NewLogger(io.Discard, &stderr, strings.NewReader(""), true, "test")
+
+	g := NewGrapher(mockDB, mockAUR, false, true, false, false, false, logger)
+
+	graph := NewGraph()
+
+	depString := "missingdep>=1.0"
+	depName := "missingdep"
+	require.NoError(t, graph.DependOn("existingNeeds", depName))
+
+	toFind := mapset.NewThreadUnsafeSet(depString)
+	_ = g.findDepsFromAUR(context.Background(), graph, "currentNeeds", toFind)
+
+	out := stderr.String()
+	require.Contains(t, out, "No AUR package found for "+depString+" (required by: currentNeeds, existingNeeds)")
+}
+
 func TestGrapher_GraphFromTargets_jellyfin(t *testing.T) {
 	mockDB := &mock.DBExecutor{
 		SyncPackageFn: func(string) mock.IPackage { return nil },

po/en.po

@@ -307,10 +307,14 @@ msgid "Name"
 msgstr ""
 
 #: pkg/dep/dep_graph.go:442
-#: pkg/dep/dep_graph.go:548
+#: pkg/dep/dep_graph.go:564
 msgid "No AUR package found for"
 msgstr ""
 
+#: pkg/dep/dep_graph.go:564
+msgid "required by"
+msgstr ""
+
 #: pkg/dep/dep_graph.go:182
 msgid "No package found for"
 msgstr ""

po/pt_BR.po

@@ -326,10 +326,14 @@ msgstr "Pacotes de debug do AUR em falta:"
 msgid "Name"
 msgstr "Nome"
 
-#: pkg/dep/dep_graph.go:442 pkg/dep/dep_graph.go:548
+#: pkg/dep/dep_graph.go:442 pkg/dep/dep_graph.go:564
 msgid "No AUR package found for"
 msgstr "Nenhum pacote AUR localizado para"
 
+#: pkg/dep/dep_graph.go:564
+msgid "required by"
+msgstr "requerido por"
+
 #: pkg/dep/dep_graph.go:182
 msgid "No package found for"
 msgstr "Nenhum pacote encontrado para"