From 2f0435beb1e735aa58005aa098fa02c6c8783e3a Mon Sep 17 00:00:00 2001
From: manjari <manjari@uber.com>
Date: Fri, 14 Aug 2026 05:46:46 +0000
Subject: [PATCH 1/5] feat(conflict): Init Tango-backed target-overlap conflict
 analyzer

---
 .../extension/conflict/tango/BUILD.bazel      |  24 +++
 submitqueue/extension/conflict/tango/tango.go | 112 ++++++++++++
 .../extension/conflict/tango/tango_test.go    | 166 ++++++++++++++++++
 3 files changed, 302 insertions(+)
 create mode 100644 submitqueue/extension/conflict/tango/BUILD.bazel
 create mode 100644 submitqueue/extension/conflict/tango/tango.go
 create mode 100644 submitqueue/extension/conflict/tango/tango_test.go

diff --git a/submitqueue/extension/conflict/tango/BUILD.bazel b/submitqueue/extension/conflict/tango/BUILD.bazel
new file mode 100644
index 000000000..c768a8edb
--- /dev/null
+++ b/submitqueue/extension/conflict/tango/BUILD.bazel
@@ -0,0 +1,24 @@
+load("@rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["tango.go"],
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/conflict/tango",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//submitqueue/entity:go_default_library",
+        "//submitqueue/extension/conflict:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["tango_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//submitqueue/entity:go_default_library",
+        "//submitqueue/extension/conflict:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
+    ],
+)
diff --git a/submitqueue/extension/conflict/tango/tango.go b/submitqueue/extension/conflict/tango/tango.go
new file mode 100644
index 000000000..05c67767a
--- /dev/null
+++ b/submitqueue/extension/conflict/tango/tango.go
@@ -0,0 +1,112 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package tango provides a conflict.Analyzer that reports a conflict between
+// two batches when their changed build targets overlap. The targets a batch
+// affects are resolved through an injected TargetResolver, whose production
+// implementation calls the Tango service.
+package tango
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/uber/submitqueue/submitqueue/entity"
+	"github.com/uber/submitqueue/submitqueue/extension/conflict"
+)
+
+// TargetResolver resolves the set of build targets a batch affects. The
+// production implementation translates the batch's changes into a Tango
+// GetChangedTargets call; tests supply a fake.
+type TargetResolver interface {
+	ChangedTargets(ctx context.Context, batch entity.Batch) ([]string, error)
+}
+
+// New returns a conflict.Analyzer that flags an in-flight batch as conflicting
+// when its changed build targets overlap with the candidate batch's, bound to
+// the queue named in cfg.
+func New(cfg conflict.Config, targets TargetResolver) conflict.Analyzer {
+	return &analyzer{cfg: cfg, targets: targets}
+}
+
+type analyzer struct {
+	cfg     conflict.Config
+	targets TargetResolver
+	// TODO: cache resolved target sets per batch ID so in-flight batches
+	// compared against successive arrivals pay only one resolution each. Consider
+	// a TTL for high-traffic queues where trunk moves fast, and a max-size cap.
+}
+
+// Analyze returns one ConflictTypeTargetOverlap Conflict per in-flight batch
+// whose changed build targets overlap with batch, preserving the in-flight
+// order. A batch that affects no targets conflicts with nothing.
+func (a *analyzer) Analyze(ctx context.Context, batch entity.Batch, inFlight []entity.Batch) ([]entity.Conflict, error) {
+	if len(inFlight) == 0 {
+		return nil, nil
+	}
+
+	// TODO: when TargetResolver fails, fall back to a queue-configured
+	// analyzer (all or none) instead of propagating the error. The queue config
+	// decides whether a Tango outage over-serializes (all) or maximizes
+	// parallelism (none).
+	candidate, err := a.resolve(ctx, batch)
+	if err != nil {
+		return nil, fmt.Errorf("failed to resolve targets for batch %s: %w", batch.ID, err)
+	}
+	if len(candidate) == 0 {
+		return nil, nil
+	}
+
+	var conflicts []entity.Conflict
+	for _, other := range inFlight {
+		keys, err := a.resolve(ctx, other)
+		if err != nil {
+			return nil, fmt.Errorf("failed to resolve targets for batch %s: %w", other.ID, err)
+		}
+		if intersects(candidate, keys) {
+			conflicts = append(conflicts, entity.Conflict{
+				BatchID: other.ID,
+				Type:    entity.ConflictTypeTargetOverlap,
+			})
+		}
+	}
+	return conflicts, nil
+}
+
+// resolve returns the set of build targets the batch affects.
+func (a *analyzer) resolve(ctx context.Context, batch entity.Batch) (map[string]struct{}, error) {
+	targets, err := a.targets.ChangedTargets(ctx, batch)
+	if err != nil {
+		return nil, err
+	}
+
+	keys := make(map[string]struct{}, len(targets))
+	for _, t := range targets {
+		keys[t] = struct{}{}
+	}
+	return keys, nil
+}
+
+// intersects reports whether the two sets share any element.
+func intersects(a, b map[string]struct{}) bool {
+	if len(b) < len(a) {
+		a, b = b, a
+	}
+	for k := range a {
+		if _, ok := b[k]; ok {
+			return true
+		}
+	}
+	return false
+}
diff --git a/submitqueue/extension/conflict/tango/tango_test.go b/submitqueue/extension/conflict/tango/tango_test.go
new file mode 100644
index 000000000..5cbd21e87
--- /dev/null
+++ b/submitqueue/extension/conflict/tango/tango_test.go
@@ -0,0 +1,166 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tango
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/uber/submitqueue/submitqueue/entity"
+	"github.com/uber/submitqueue/submitqueue/extension/conflict"
+)
+
+// fakeResolver is an in-test TargetResolver that returns pre-configured target
+// sets per batch ID.
+type fakeResolver struct {
+	targets map[string][]string
+	err     error
+}
+
+func newFakeResolver() *fakeResolver {
+	return &fakeResolver{targets: make(map[string][]string)}
+}
+
+func (f *fakeResolver) set(batchID string, targets ...string) *fakeResolver {
+	f.targets[batchID] = targets
+	return f
+}
+
+func (f *fakeResolver) failWith(err error) *fakeResolver {
+	f.err = err
+	return f
+}
+
+func (f *fakeResolver) ChangedTargets(_ context.Context, batch entity.Batch) ([]string, error) {
+	if f.err != nil {
+		return nil, f.err
+	}
+	return f.targets[batch.ID], nil
+}
+
+func cfg() conflict.Config {
+	return conflict.Config{QueueName: "test-queue"}
+}
+
+func TestAnalyze(t *testing.T) {
+	tests := []struct {
+		name        string
+		candidate   string
+		candTargets []string
+		inFlight    []struct {
+			id      string
+			targets []string
+		}
+		wantBatches []string
+	}{
+		{
+			name:        "overlap on a shared target conflicts",
+			candidate:   "cand",
+			candTargets: []string{"//foo:lib", "//bar:lib"},
+			inFlight: []struct {
+				id      string
+				targets []string
+			}{
+				{id: "x", targets: []string{"//bar:lib", "//baz:lib"}},
+			},
+			wantBatches: []string{"x"},
+		},
+		{
+			name:        "disjoint targets do not conflict",
+			candidate:   "cand",
+			candTargets: []string{"//foo:lib"},
+			inFlight: []struct {
+				id      string
+				targets []string
+			}{
+				{id: "x", targets: []string{"//bar:lib"}},
+			},
+			wantBatches: nil,
+		},
+		{
+			name:        "only overlapping in-flight batches are reported, in order",
+			candidate:   "cand",
+			candTargets: []string{"//foo:lib"},
+			inFlight: []struct {
+				id      string
+				targets []string
+			}{
+				{id: "x", targets: []string{"//foo:lib"}},
+				{id: "y", targets: []string{"//bar:lib"}},
+				{id: "z", targets: []string{"//foo:lib"}},
+			},
+			wantBatches: []string{"x", "z"},
+		},
+		{
+			name:        "candidate with no targets conflicts with nothing",
+			candidate:   "cand",
+			candTargets: nil,
+			inFlight: []struct {
+				id      string
+				targets []string
+			}{
+				{id: "x", targets: []string{"//foo:lib"}},
+			},
+			wantBatches: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resolver := newFakeResolver().set(tt.candidate, tt.candTargets...)
+			inFlight := make([]entity.Batch, 0, len(tt.inFlight))
+			for _, f := range tt.inFlight {
+				resolver.set(f.id, f.targets...)
+				inFlight = append(inFlight, entity.Batch{ID: f.id})
+			}
+
+			got, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: tt.candidate}, inFlight)
+			require.NoError(t, err)
+
+			var ids []string
+			for _, c := range got {
+				assert.Equal(t, entity.ConflictTypeTargetOverlap, c.Type)
+				ids = append(ids, c.BatchID)
+			}
+			assert.Equal(t, tt.wantBatches, ids)
+		})
+	}
+}
+
+func TestAnalyze_EmptyInFlight(t *testing.T) {
+	got, err := New(cfg(), newFakeResolver()).Analyze(context.Background(), entity.Batch{ID: "cand"}, nil)
+	require.NoError(t, err)
+	assert.Empty(t, got)
+}
+
+func TestAnalyze_ResolverError(t *testing.T) {
+	sentinel := errors.New("tango unavailable")
+
+	t.Run("candidate resolution fails", func(t *testing.T) {
+		resolver := newFakeResolver().failWith(sentinel)
+		_, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
+		require.ErrorIs(t, err, sentinel)
+	})
+
+	t.Run("in-flight resolution fails", func(t *testing.T) {
+		resolver := newFakeResolver().set("cand", "//foo:lib").failWith(sentinel)
+		_, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
+		require.ErrorIs(t, err, sentinel)
+	})
+}

From b06bb062668811403c90341bd63d4a0eb5e439e3 Mon Sep 17 00:00:00 2001
From: manjari <manjari@uber.com>
Date: Mon, 17 Aug 2026 14:51:51 +0000
Subject: [PATCH 2/5] feat(conflict): Move targets resolver and implementation
 under dependency

---
 .../conflict/tango/BUILD.bazel                |  3 +-
 .../{ => dependency}/conflict/tango/tango.go  | 16 +++------
 .../conflict/tango/tango_test.go              |  0
 .../extension/dependency/resolver/BUILD.bazel |  9 +++++
 .../dependency/resolver/targetresolver.go     | 33 +++++++++++++++++++
 5 files changed, 49 insertions(+), 12 deletions(-)
 rename submitqueue/extension/{ => dependency}/conflict/tango/BUILD.bazel (87%)
 rename submitqueue/extension/{ => dependency}/conflict/tango/tango.go (86%)
 rename submitqueue/extension/{ => dependency}/conflict/tango/tango_test.go (100%)
 create mode 100644 submitqueue/extension/dependency/resolver/BUILD.bazel
 create mode 100644 submitqueue/extension/dependency/resolver/targetresolver.go

diff --git a/submitqueue/extension/conflict/tango/BUILD.bazel b/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
similarity index 87%
rename from submitqueue/extension/conflict/tango/BUILD.bazel
rename to submitqueue/extension/dependency/conflict/tango/BUILD.bazel
index c768a8edb..9c3e0ded9 100644
--- a/submitqueue/extension/conflict/tango/BUILD.bazel
+++ b/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
@@ -3,11 +3,12 @@ load("@rules_go//go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = ["tango.go"],
-    importpath = "github.com/uber/submitqueue/submitqueue/extension/conflict/tango",
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/tango",
     visibility = ["//visibility:public"],
     deps = [
         "//submitqueue/entity:go_default_library",
         "//submitqueue/extension/conflict:go_default_library",
+        "//submitqueue/extension/dependency/resolver:go_default_library",
     ],
 )
 
diff --git a/submitqueue/extension/conflict/tango/tango.go b/submitqueue/extension/dependency/conflict/tango/tango.go
similarity index 86%
rename from submitqueue/extension/conflict/tango/tango.go
rename to submitqueue/extension/dependency/conflict/tango/tango.go
index 05c67767a..2c92c1ffd 100644
--- a/submitqueue/extension/conflict/tango/tango.go
+++ b/submitqueue/extension/dependency/conflict/tango/tango.go
@@ -14,8 +14,8 @@
 
 // Package tango provides a conflict.Analyzer that reports a conflict between
 // two batches when their changed build targets overlap. The targets a batch
-// affects are resolved through an injected TargetResolver, whose production
-// implementation calls the Tango service.
+// affects are resolved through an injected resolver.TargetResolver, whose
+// production implementation calls the Tango service.
 package tango
 
 import (
@@ -24,25 +24,19 @@ import (
 
 	"github.com/uber/submitqueue/submitqueue/entity"
 	"github.com/uber/submitqueue/submitqueue/extension/conflict"
+	"github.com/uber/submitqueue/submitqueue/extension/dependency/resolver"
 )
 
-// TargetResolver resolves the set of build targets a batch affects. The
-// production implementation translates the batch's changes into a Tango
-// GetChangedTargets call; tests supply a fake.
-type TargetResolver interface {
-	ChangedTargets(ctx context.Context, batch entity.Batch) ([]string, error)
-}
-
 // New returns a conflict.Analyzer that flags an in-flight batch as conflicting
 // when its changed build targets overlap with the candidate batch's, bound to
 // the queue named in cfg.
-func New(cfg conflict.Config, targets TargetResolver) conflict.Analyzer {
+func New(cfg conflict.Config, targets resolver.TargetResolver) conflict.Analyzer {
 	return &analyzer{cfg: cfg, targets: targets}
 }
 
 type analyzer struct {
 	cfg     conflict.Config
-	targets TargetResolver
+	targets resolver.TargetResolver
 	// TODO: cache resolved target sets per batch ID so in-flight batches
 	// compared against successive arrivals pay only one resolution each. Consider
 	// a TTL for high-traffic queues where trunk moves fast, and a max-size cap.
diff --git a/submitqueue/extension/conflict/tango/tango_test.go b/submitqueue/extension/dependency/conflict/tango/tango_test.go
similarity index 100%
rename from submitqueue/extension/conflict/tango/tango_test.go
rename to submitqueue/extension/dependency/conflict/tango/tango_test.go
diff --git a/submitqueue/extension/dependency/resolver/BUILD.bazel b/submitqueue/extension/dependency/resolver/BUILD.bazel
new file mode 100644
index 000000000..7944b6623
--- /dev/null
+++ b/submitqueue/extension/dependency/resolver/BUILD.bazel
@@ -0,0 +1,9 @@
+load("@rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["targetresolver.go"],
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/resolver",
+    visibility = ["//visibility:public"],
+    deps = ["//submitqueue/entity:go_default_library"],
+)
diff --git a/submitqueue/extension/dependency/resolver/targetresolver.go b/submitqueue/extension/dependency/resolver/targetresolver.go
new file mode 100644
index 000000000..387da245c
--- /dev/null
+++ b/submitqueue/extension/dependency/resolver/targetresolver.go
@@ -0,0 +1,33 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package resolver defines the TargetResolver interface for resolving the set
+// of build targets a batch affects. The interface is deliberately free of
+// Tango wire types so that each deployment can provide its own adapter against
+// whatever proto import path its monorepo uses — the analyzer sees only batch
+// identity in and target names out.
+package resolver
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/submitqueue/entity"
+)
+
+// TargetResolver resolves the set of build targets a batch affects. The
+// production implementation translates the batch's changes into a Tango
+// GetChangedTargets call; tests supply a fake.
+type TargetResolver interface {
+	ChangedTargets(ctx context.Context, batch entity.Batch) ([]string, error)
+}

From 484dbcd1477dffa478ed62cf6a1208a01639da63 Mon Sep 17 00:00:00 2001
From: manjari <manjari@uber.com>
Date: Fri, 21 Aug 2026 18:49:42 +0000
Subject: [PATCH 3/5] feat(conflict): Rename and iterate the interface contract

---
 .../{tango => targetoverlap}/BUILD.bazel      |  7 +++--
 .../targetoverlap.go}                         | 14 +++++-----
 .../targetoverlap_test.go}                    | 28 +++++++++++--------
 .../dependency/resolver/targetresolver.go     | 14 ++++++++--
 4 files changed, 40 insertions(+), 23 deletions(-)
 rename submitqueue/extension/dependency/conflict/{tango => targetoverlap}/BUILD.bazel (80%)
 rename submitqueue/extension/dependency/conflict/{tango/tango.go => targetoverlap/targetoverlap.go} (88%)
 rename submitqueue/extension/dependency/conflict/{tango/tango_test.go => targetoverlap/targetoverlap_test.go} (81%)

diff --git a/submitqueue/extension/dependency/conflict/tango/BUILD.bazel b/submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel
similarity index 80%
rename from submitqueue/extension/dependency/conflict/tango/BUILD.bazel
rename to submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel
index 9c3e0ded9..7d05516b7 100644
--- a/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
+++ b/submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel
@@ -2,8 +2,8 @@ load("@rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["tango.go"],
-    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/tango",
+    srcs = ["targetoverlap.go"],
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/targetoverlap",
     visibility = ["//visibility:public"],
     deps = [
         "//submitqueue/entity:go_default_library",
@@ -14,11 +14,12 @@ go_library(
 
 go_test(
     name = "go_default_test",
-    srcs = ["tango_test.go"],
+    srcs = ["targetoverlap_test.go"],
     embed = [":go_default_library"],
     deps = [
         "//submitqueue/entity:go_default_library",
         "//submitqueue/extension/conflict:go_default_library",
+        "//submitqueue/extension/dependency/resolver:go_default_library",
         "@com_github_stretchr_testify//assert:go_default_library",
         "@com_github_stretchr_testify//require:go_default_library",
     ],
diff --git a/submitqueue/extension/dependency/conflict/tango/tango.go b/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go
similarity index 88%
rename from submitqueue/extension/dependency/conflict/tango/tango.go
rename to submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go
index 2c92c1ffd..6f77d296b 100644
--- a/submitqueue/extension/dependency/conflict/tango/tango.go
+++ b/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go
@@ -12,11 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package tango provides a conflict.Analyzer that reports a conflict between
-// two batches when their changed build targets overlap. The targets a batch
-// affects are resolved through an injected resolver.TargetResolver, whose
-// production implementation calls the Tango service.
-package tango
+// Package targetoverlap provides a conflict.Analyzer that reports a conflict
+// between two batches when their changed build targets overlap. The targets a
+// batch affects are resolved through an injected resolver.TargetResolver,
+// keeping the analyzer independent of any particular target-resolution backend.
+package targetoverlap
 
 import (
 	"context"
@@ -52,7 +52,7 @@ func (a *analyzer) Analyze(ctx context.Context, batch entity.Batch, inFlight []e
 
 	// TODO: when TargetResolver fails, fall back to a queue-configured
 	// analyzer (all or none) instead of propagating the error. The queue config
-	// decides whether a Tango outage over-serializes (all) or maximizes
+	// decides whether a resolver outage over-serializes (all) or maximizes
 	// parallelism (none).
 	candidate, err := a.resolve(ctx, batch)
 	if err != nil {
@@ -87,7 +87,7 @@ func (a *analyzer) resolve(ctx context.Context, batch entity.Batch) (map[string]
 
 	keys := make(map[string]struct{}, len(targets))
 	for _, t := range targets {
-		keys[t] = struct{}{}
+		keys[t.Name] = struct{}{}
 	}
 	return keys, nil
 }
diff --git a/submitqueue/extension/dependency/conflict/tango/tango_test.go b/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go
similarity index 81%
rename from submitqueue/extension/dependency/conflict/tango/tango_test.go
rename to submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go
index 5cbd21e87..66154e713 100644
--- a/submitqueue/extension/dependency/conflict/tango/tango_test.go
+++ b/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package tango
+package targetoverlap
 
 import (
 	"context"
@@ -24,6 +24,7 @@ import (
 
 	"github.com/uber/submitqueue/submitqueue/entity"
 	"github.com/uber/submitqueue/submitqueue/extension/conflict"
+	"github.com/uber/submitqueue/submitqueue/extension/dependency/resolver"
 )
 
 // fakeResolver is an in-test TargetResolver that returns pre-configured target
@@ -47,11 +48,16 @@ func (f *fakeResolver) failWith(err error) *fakeResolver {
 	return f
 }
 
-func (f *fakeResolver) ChangedTargets(_ context.Context, batch entity.Batch) ([]string, error) {
+func (f *fakeResolver) ChangedTargets(_ context.Context, batch entity.Batch) ([]resolver.Target, error) {
 	if f.err != nil {
 		return nil, f.err
 	}
-	return f.targets[batch.ID], nil
+	names := f.targets[batch.ID]
+	targets := make([]resolver.Target, len(names))
+	for i, n := range names {
+		targets[i] = resolver.Target{Name: n}
+	}
+	return targets, nil
 }
 
 func cfg() conflict.Config {
@@ -123,14 +129,14 @@ func TestAnalyze(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			resolver := newFakeResolver().set(tt.candidate, tt.candTargets...)
+			r := newFakeResolver().set(tt.candidate, tt.candTargets...)
 			inFlight := make([]entity.Batch, 0, len(tt.inFlight))
 			for _, f := range tt.inFlight {
-				resolver.set(f.id, f.targets...)
+				r.set(f.id, f.targets...)
 				inFlight = append(inFlight, entity.Batch{ID: f.id})
 			}
 
-			got, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: tt.candidate}, inFlight)
+			got, err := New(cfg(), r).Analyze(context.Background(), entity.Batch{ID: tt.candidate}, inFlight)
 			require.NoError(t, err)
 
 			var ids []string
@@ -150,17 +156,17 @@ func TestAnalyze_EmptyInFlight(t *testing.T) {
 }
 
 func TestAnalyze_ResolverError(t *testing.T) {
-	sentinel := errors.New("tango unavailable")
+	sentinel := errors.New("resolver unavailable")
 
 	t.Run("candidate resolution fails", func(t *testing.T) {
-		resolver := newFakeResolver().failWith(sentinel)
-		_, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
+		r := newFakeResolver().failWith(sentinel)
+		_, err := New(cfg(), r).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
 		require.ErrorIs(t, err, sentinel)
 	})
 
 	t.Run("in-flight resolution fails", func(t *testing.T) {
-		resolver := newFakeResolver().set("cand", "//foo:lib").failWith(sentinel)
-		_, err := New(cfg(), resolver).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
+		r := newFakeResolver().set("cand", "//foo:lib").failWith(sentinel)
+		_, err := New(cfg(), r).Analyze(context.Background(), entity.Batch{ID: "cand"}, []entity.Batch{{ID: "x"}})
 		require.ErrorIs(t, err, sentinel)
 	})
 }
diff --git a/submitqueue/extension/dependency/resolver/targetresolver.go b/submitqueue/extension/dependency/resolver/targetresolver.go
index 387da245c..8b77c05d0 100644
--- a/submitqueue/extension/dependency/resolver/targetresolver.go
+++ b/submitqueue/extension/dependency/resolver/targetresolver.go
@@ -16,7 +16,7 @@
 // of build targets a batch affects. The interface is deliberately free of
 // Tango wire types so that each deployment can provide its own adapter against
 // whatever proto import path its monorepo uses — the analyzer sees only batch
-// identity in and target names out.
+// identity in and targets out.
 package resolver
 
 import (
@@ -25,9 +25,19 @@ import (
 	"github.com/uber/submitqueue/submitqueue/entity"
 )
 
+// Target is a build target a batch affects.
+type Target struct {
+	// Name identifies the target (e.g. "//service/foo:lib").
+	Name string
+	// Attributes carries backend-specific metadata the analyzer does not
+	// interpret today. Future consumers (e.g. conflict relaxation) can read
+	// keys like "distance" or "rule_type" without an interface change.
+	Attributes map[string]string
+}
+
 // TargetResolver resolves the set of build targets a batch affects. The
 // production implementation translates the batch's changes into a Tango
 // GetChangedTargets call; tests supply a fake.
 type TargetResolver interface {
-	ChangedTargets(ctx context.Context, batch entity.Batch) ([]string, error)
+	ChangedTargets(ctx context.Context, batch entity.Batch) ([]Target, error)
 }

From 13f58c2870fbd835a2844bf5b3dc374bc6c27ce1 Mon Sep 17 00:00:00 2001
From: manjari <manjari@uber.com>
Date: Wed, 26 Aug 2026 20:33:10 +0000
Subject: [PATCH 4/5] feat(conflict): Lightweight interface for tango resolver
 and tango analyzer impl

---
 .../{targetoverlap => tango}/BUILD.bazel      |  8 ++--
 .../targetoverlap.go => tango/tango.go}       | 42 +++++++++++++-----
 .../tango_test.go}                            | 11 +++--
 .../extension/dependency/resolver/BUILD.bazel |  9 ----
 .../dependency/resolver/targetresolver.go     | 43 -------------------
 5 files changed, 40 insertions(+), 73 deletions(-)
 rename submitqueue/extension/dependency/conflict/{targetoverlap => tango}/BUILD.bazel (72%)
 rename submitqueue/extension/dependency/conflict/{targetoverlap/targetoverlap.go => tango/tango.go} (65%)
 rename submitqueue/extension/dependency/conflict/{targetoverlap/targetoverlap_test.go => tango/tango_test.go} (94%)
 delete mode 100644 submitqueue/extension/dependency/resolver/BUILD.bazel
 delete mode 100644 submitqueue/extension/dependency/resolver/targetresolver.go

diff --git a/submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel b/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
similarity index 72%
rename from submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel
rename to submitqueue/extension/dependency/conflict/tango/BUILD.bazel
index 7d05516b7..181b93a8c 100644
--- a/submitqueue/extension/dependency/conflict/targetoverlap/BUILD.bazel
+++ b/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
@@ -2,24 +2,22 @@ load("@rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["targetoverlap.go"],
-    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/targetoverlap",
+    srcs = ["tango.go"],
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/tango",
     visibility = ["//visibility:public"],
     deps = [
         "//submitqueue/entity:go_default_library",
         "//submitqueue/extension/conflict:go_default_library",
-        "//submitqueue/extension/dependency/resolver:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["targetoverlap_test.go"],
+    srcs = ["tango_test.go"],
     embed = [":go_default_library"],
     deps = [
         "//submitqueue/entity:go_default_library",
         "//submitqueue/extension/conflict:go_default_library",
-        "//submitqueue/extension/dependency/resolver:go_default_library",
         "@com_github_stretchr_testify//assert:go_default_library",
         "@com_github_stretchr_testify//require:go_default_library",
     ],
diff --git a/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go b/submitqueue/extension/dependency/conflict/tango/tango.go
similarity index 65%
rename from submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go
rename to submitqueue/extension/dependency/conflict/tango/tango.go
index 6f77d296b..fc71dc4d0 100644
--- a/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap.go
+++ b/submitqueue/extension/dependency/conflict/tango/tango.go
@@ -12,11 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package targetoverlap provides a conflict.Analyzer that reports a conflict
-// between two batches when their changed build targets overlap. The targets a
-// batch affects are resolved through an injected resolver.TargetResolver,
-// keeping the analyzer independent of any particular target-resolution backend.
-package targetoverlap
+// Package tango provides a conflict.Analyzer that reports a conflict between
+// two batches when their changed build targets overlap. The targets a batch
+// affects are resolved through an injected TargetResolver, whose production
+// implementation calls the Tango service. The interface is deliberately free
+// of Tango wire types so that each deployment can provide its own adapter
+// against whatever proto import path its monorepo uses.
+package tango
 
 import (
 	"context"
@@ -24,19 +26,39 @@ import (
 
 	"github.com/uber/submitqueue/submitqueue/entity"
 	"github.com/uber/submitqueue/submitqueue/extension/conflict"
-	"github.com/uber/submitqueue/submitqueue/extension/dependency/resolver"
 )
 
+// Target is a build target a batch affects, carrying the fields Tango reports
+// for each changed target. The analyzer reads only Name for overlap today;
+// ChangeType and Distance are available for future consumers such as conflict
+// relaxation.
+type Target struct {
+	// Name identifies the target (e.g. "//service/foo:lib").
+	Name string
+	// ChangeType classifies how the target changed: "new", "deleted", or "changed".
+	ChangeType string
+	// Distance from the nearest directly changed source file in the reverse
+	// dependency graph. 0 = directly changed, 1+ = transitive.
+	Distance int
+}
+
+// TargetResolver resolves the set of build targets a batch affects. The
+// production implementation translates the batch's changes into a Tango
+// GetChangedTargets call; tests supply a fake.
+type TargetResolver interface {
+	ChangedTargets(ctx context.Context, batch entity.Batch) ([]Target, error)
+}
+
 // New returns a conflict.Analyzer that flags an in-flight batch as conflicting
 // when its changed build targets overlap with the candidate batch's, bound to
 // the queue named in cfg.
-func New(cfg conflict.Config, targets resolver.TargetResolver) conflict.Analyzer {
+func New(cfg conflict.Config, targets TargetResolver) conflict.Analyzer {
 	return &analyzer{cfg: cfg, targets: targets}
 }
 
 type analyzer struct {
 	cfg     conflict.Config
-	targets resolver.TargetResolver
+	targets TargetResolver
 	// TODO: cache resolved target sets per batch ID so in-flight batches
 	// compared against successive arrivals pay only one resolution each. Consider
 	// a TTL for high-traffic queues where trunk moves fast, and a max-size cap.
@@ -52,7 +74,7 @@ func (a *analyzer) Analyze(ctx context.Context, batch entity.Batch, inFlight []e
 
 	// TODO: when TargetResolver fails, fall back to a queue-configured
 	// analyzer (all or none) instead of propagating the error. The queue config
-	// decides whether a resolver outage over-serializes (all) or maximizes
+	// decides whether a Tango outage over-serializes (all) or maximizes
 	// parallelism (none).
 	candidate, err := a.resolve(ctx, batch)
 	if err != nil {
@@ -78,7 +100,7 @@ func (a *analyzer) Analyze(ctx context.Context, batch entity.Batch, inFlight []e
 	return conflicts, nil
 }
 
-// resolve returns the set of build targets the batch affects.
+// resolve returns the set of target names the batch affects.
 func (a *analyzer) resolve(ctx context.Context, batch entity.Batch) (map[string]struct{}, error) {
 	targets, err := a.targets.ChangedTargets(ctx, batch)
 	if err != nil {
diff --git a/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go b/submitqueue/extension/dependency/conflict/tango/tango_test.go
similarity index 94%
rename from submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go
rename to submitqueue/extension/dependency/conflict/tango/tango_test.go
index 66154e713..1dd5de38a 100644
--- a/submitqueue/extension/dependency/conflict/targetoverlap/targetoverlap_test.go
+++ b/submitqueue/extension/dependency/conflict/tango/tango_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package targetoverlap
+package tango
 
 import (
 	"context"
@@ -24,7 +24,6 @@ import (
 
 	"github.com/uber/submitqueue/submitqueue/entity"
 	"github.com/uber/submitqueue/submitqueue/extension/conflict"
-	"github.com/uber/submitqueue/submitqueue/extension/dependency/resolver"
 )
 
 // fakeResolver is an in-test TargetResolver that returns pre-configured target
@@ -48,14 +47,14 @@ func (f *fakeResolver) failWith(err error) *fakeResolver {
 	return f
 }
 
-func (f *fakeResolver) ChangedTargets(_ context.Context, batch entity.Batch) ([]resolver.Target, error) {
+func (f *fakeResolver) ChangedTargets(_ context.Context, batch entity.Batch) ([]Target, error) {
 	if f.err != nil {
 		return nil, f.err
 	}
 	names := f.targets[batch.ID]
-	targets := make([]resolver.Target, len(names))
+	targets := make([]Target, len(names))
 	for i, n := range names {
-		targets[i] = resolver.Target{Name: n}
+		targets[i] = Target{Name: n}
 	}
 	return targets, nil
 }
@@ -156,7 +155,7 @@ func TestAnalyze_EmptyInFlight(t *testing.T) {
 }
 
 func TestAnalyze_ResolverError(t *testing.T) {
-	sentinel := errors.New("resolver unavailable")
+	sentinel := errors.New("tango unavailable")
 
 	t.Run("candidate resolution fails", func(t *testing.T) {
 		r := newFakeResolver().failWith(sentinel)
diff --git a/submitqueue/extension/dependency/resolver/BUILD.bazel b/submitqueue/extension/dependency/resolver/BUILD.bazel
deleted file mode 100644
index 7944b6623..000000000
--- a/submitqueue/extension/dependency/resolver/BUILD.bazel
+++ /dev/null
@@ -1,9 +0,0 @@
-load("@rules_go//go:def.bzl", "go_library")
-
-go_library(
-    name = "go_default_library",
-    srcs = ["targetresolver.go"],
-    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/resolver",
-    visibility = ["//visibility:public"],
-    deps = ["//submitqueue/entity:go_default_library"],
-)
diff --git a/submitqueue/extension/dependency/resolver/targetresolver.go b/submitqueue/extension/dependency/resolver/targetresolver.go
deleted file mode 100644
index 8b77c05d0..000000000
--- a/submitqueue/extension/dependency/resolver/targetresolver.go
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright (c) 2026 Uber Technologies, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package resolver defines the TargetResolver interface for resolving the set
-// of build targets a batch affects. The interface is deliberately free of
-// Tango wire types so that each deployment can provide its own adapter against
-// whatever proto import path its monorepo uses — the analyzer sees only batch
-// identity in and targets out.
-package resolver
-
-import (
-	"context"
-
-	"github.com/uber/submitqueue/submitqueue/entity"
-)
-
-// Target is a build target a batch affects.
-type Target struct {
-	// Name identifies the target (e.g. "//service/foo:lib").
-	Name string
-	// Attributes carries backend-specific metadata the analyzer does not
-	// interpret today. Future consumers (e.g. conflict relaxation) can read
-	// keys like "distance" or "rule_type" without an interface change.
-	Attributes map[string]string
-}
-
-// TargetResolver resolves the set of build targets a batch affects. The
-// production implementation translates the batch's changes into a Tango
-// GetChangedTargets call; tests supply a fake.
-type TargetResolver interface {
-	ChangedTargets(ctx context.Context, batch entity.Batch) ([]Target, error)
-}

From 47274a76d909fecbe82dcc203602425bb12d0c42 Mon Sep 17 00:00:00 2001
From: manjari <manjari@uber.com>
Date: Wed, 26 Aug 2026 21:47:08 +0000
Subject: [PATCH 5/5] feat(conflict): Move tango anazlyer under conflict
 extension

---
 .../extension/{dependency => }/conflict/tango/BUILD.bazel       | 2 +-
 submitqueue/extension/{dependency => }/conflict/tango/tango.go  | 0
 .../extension/{dependency => }/conflict/tango/tango_test.go     | 0
 3 files changed, 1 insertion(+), 1 deletion(-)
 rename submitqueue/extension/{dependency => }/conflict/tango/BUILD.bazel (95%)
 rename submitqueue/extension/{dependency => }/conflict/tango/tango.go (100%)
 rename submitqueue/extension/{dependency => }/conflict/tango/tango_test.go (100%)

diff --git a/submitqueue/extension/dependency/conflict/tango/BUILD.bazel b/submitqueue/extension/conflict/tango/BUILD.bazel
similarity index 95%
rename from submitqueue/extension/dependency/conflict/tango/BUILD.bazel
rename to submitqueue/extension/conflict/tango/BUILD.bazel
index 181b93a8c..c768a8edb 100644
--- a/submitqueue/extension/dependency/conflict/tango/BUILD.bazel
+++ b/submitqueue/extension/conflict/tango/BUILD.bazel
@@ -3,7 +3,7 @@ load("@rules_go//go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = ["tango.go"],
-    importpath = "github.com/uber/submitqueue/submitqueue/extension/dependency/conflict/tango",
+    importpath = "github.com/uber/submitqueue/submitqueue/extension/conflict/tango",
     visibility = ["//visibility:public"],
     deps = [
         "//submitqueue/entity:go_default_library",
diff --git a/submitqueue/extension/dependency/conflict/tango/tango.go b/submitqueue/extension/conflict/tango/tango.go
similarity index 100%
rename from submitqueue/extension/dependency/conflict/tango/tango.go
rename to submitqueue/extension/conflict/tango/tango.go
diff --git a/submitqueue/extension/dependency/conflict/tango/tango_test.go b/submitqueue/extension/conflict/tango/tango_test.go
similarity index 100%
rename from submitqueue/extension/dependency/conflict/tango/tango_test.go
rename to submitqueue/extension/conflict/tango/tango_test.go