feat: add transaction code resolve helpers for bindercli

xaionaro@dx.center · xaionaro@dx.center · commit 9e0031e14965 · 2026-04-05T13:11:31.000Z
Add resolveCodeToMethod (reverse lookup), resolveMethodToCode (forward
lookup), and getActiveTable (extract VersionTable from a Conn) to
support upcoming CLI commands that translate between method names and
transaction codes.
diff --git a/cmd/bindercli/resolve.go b/cmd/bindercli/resolve.go
@@ -0,0 +1,56 @@
+//go:build linux
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/AndroidGoLab/binder/binder"
+	"github.com/AndroidGoLab/binder/binder/versionaware"
+)
+
+// resolveCodeToMethod performs reverse lookup: given a descriptor and
+// transaction code, returns the method name. Returns ("", false) if not found.
+func resolveCodeToMethod(
+	table versionaware.VersionTable,
+	descriptor string,
+	code binder.TransactionCode,
+) (string, bool) {
+	methods, ok := table[descriptor]
+	if !ok {
+		return "", false
+	}
+	for name, c := range methods {
+		if c == code {
+			return name, true
+		}
+	}
+	return "", false
+}
+
+// resolveMethodToCode performs forward lookup: given a descriptor and
+// method name, returns the transaction code. Returns (0, false) if not found.
+func resolveMethodToCode(
+	table versionaware.VersionTable,
+	descriptor string,
+	method string,
+) (binder.TransactionCode, bool) {
+	code := table.Resolve(descriptor, method)
+	if code == 0 {
+		return 0, false
+	}
+	return code, true
+}
+
+// getActiveTable extracts the active VersionTable from a Conn's transport.
+// Returns an error if the transport is not version-aware.
+func getActiveTable(c *Conn) (versionaware.VersionTable, error) {
+	if c == nil {
+		return nil, fmt.Errorf("connection is nil")
+	}
+	vat, ok := c.Transport.(*versionaware.Transport)
+	if !ok {
+		return nil, fmt.Errorf("transport is not version-aware")
+	}
+	return vat.ActiveTable(), nil
+}
diff --git a/cmd/bindercli/resolve_test.go b/cmd/bindercli/resolve_test.go
@@ -0,0 +1,71 @@
+//go:build linux
+
+package main
+
+import (
+	"testing"
+
+	"github.com/AndroidGoLab/binder/binder"
+	"github.com/AndroidGoLab/binder/binder/versionaware"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestResolveCodeToMethod(t *testing.T) {
+	table := versionaware.VersionTable{
+		"android.app.IFoo": {
+			"doThing": binder.FirstCallTransaction + 0,
+			"doOther": binder.FirstCallTransaction + 1,
+		},
+	}
+
+	name, ok := resolveCodeToMethod(table, "android.app.IFoo", binder.FirstCallTransaction+1)
+	assert.True(t, ok)
+	assert.Equal(t, "doOther", name)
+}
+
+func TestResolveCodeToMethod_NotFound(t *testing.T) {
+	table := versionaware.VersionTable{
+		"android.app.IFoo": {
+			"doThing": binder.FirstCallTransaction + 0,
+		},
+	}
+
+	_, ok := resolveCodeToMethod(table, "android.app.IFoo", binder.FirstCallTransaction+99)
+	assert.False(t, ok)
+}
+
+func TestResolveCodeToMethod_UnknownDescriptor(t *testing.T) {
+	table := versionaware.VersionTable{}
+
+	_, ok := resolveCodeToMethod(table, "android.app.IFoo", binder.FirstCallTransaction)
+	assert.False(t, ok)
+}
+
+func TestResolveMethodToCode(t *testing.T) {
+	table := versionaware.VersionTable{
+		"android.app.IFoo": {
+			"doThing": binder.FirstCallTransaction + 0,
+			"doOther": binder.FirstCallTransaction + 1,
+		},
+	}
+
+	code, ok := resolveMethodToCode(table, "android.app.IFoo", "doOther")
+	assert.True(t, ok)
+	assert.Equal(t, binder.FirstCallTransaction+1, code)
+}
+
+func TestResolveMethodToCode_NotFound(t *testing.T) {
+	table := versionaware.VersionTable{
+		"android.app.IFoo": {
+			"doThing": binder.FirstCallTransaction + 0,
+		},
+	}
+
+	_, ok := resolveMethodToCode(table, "android.app.IFoo", "noSuchMethod")
+	assert.False(t, ok)
+}
+
+func TestGetActiveTable_NilConn(t *testing.T) {
+	_, err := getActiveTable(nil)
+	assert.Error(t, err)
+}
