Artifact [8044a7e938]

Artifact 8044a7e9384860f12d96f123cc055bf56e1f2b8fa24e731433dbbe35351f0043:

• File internal/merge/threeway_test.go — part of check-in [f5744359d3] at 2026-04-19 16:30:54 on branch trunk — Initial open source release

  libfossil is a pure-Go implementation of the Fossil SCM, reading and writing the same .fossil SQLite repository format as upstream Fossil.

  This is the first public release of code that previously lived in a private repository. The module path is github.com/danmestas/libfossil and the binary is named libfossil to avoid $PATH collisions with upstream fossil.

  Included: - Repo lifecycle (create, clone), checkout/checkin, timeline, merge, diff, annotate, shun, tag, branch, bisect, stash, undo/redo - Sync-over-HTTP protocol (client and handler) - Two SQLite drivers: modernc (pure Go, default) and ncruces (wasm-capable) - Observer interfaces (SyncObserver, CheckoutObserver) with an optional OpenTelemetry implementation in observer/otel (separate submodule) - Deterministic simulation testing harness with BUGGIFY fault injection - Kong-based embeddable CLI under cli/ and a standalone binary under cmd/libfossil/ (user: [email protected], size: 4641) [annotate] [blame] [check-ins using]

package merge

import (
	"strings"
	"testing"
)

func TestThreeWayIdentical(t *testing.T) {
	base := []byte("same\n")
	r, err := (&ThreeWayText{}).Merge(base, base, base)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatal("expected clean merge")
	}
	if string(r.Content) != "same\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayOnlyLocalChanged(t *testing.T) {
	base := []byte("line1\nline2\nline3\n")
	local := []byte("line1\nMODIFIED\nline3\n")
	remote := []byte("line1\nline2\nline3\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatal("expected clean merge")
	}
	if string(r.Content) != "line1\nMODIFIED\nline3\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayOnlyRemoteChanged(t *testing.T) {
	base := []byte("line1\nline2\nline3\n")
	local := []byte("line1\nline2\nline3\n")
	remote := []byte("line1\nline2\nREMOTE\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatal("expected clean merge")
	}
	if string(r.Content) != "line1\nline2\nREMOTE\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayBothChangedSame(t *testing.T) {
	base := []byte("old\n")
	local := []byte("new\n")
	remote := []byte("new\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatal("expected clean merge (both made same change)")
	}
}

func TestThreeWayNonOverlapping(t *testing.T) {
	base := []byte("aaa\nbbb\nccc\n")
	local := []byte("AAA\nbbb\nccc\n")
	remote := []byte("aaa\nbbb\nCCC\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatalf("expected clean merge, got %d conflicts", len(r.Conflicts))
	}
	if string(r.Content) != "AAA\nbbb\nCCC\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayConflict(t *testing.T) {
	base := []byte("original\n")
	local := []byte("local version\n")
	remote := []byte("remote version\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if r.Clean {
		t.Fatal("expected conflict")
	}
	if len(r.Conflicts) == 0 {
		t.Fatal("expected at least one conflict")
	}
	if !strings.Contains(string(r.Content), "<<<<<<< LOCAL") {
		t.Fatalf("expected conflict markers, got %q", r.Content)
	}
	if !strings.Contains(string(r.Content), "local version") {
		t.Fatalf("expected local content in markers")
	}
	if !strings.Contains(string(r.Content), "remote version") {
		t.Fatalf("expected remote content in markers")
	}
}

func TestThreeWayLocalAddsLines(t *testing.T) {
	base := []byte("a\nc\n")
	local := []byte("a\nb\nc\n")
	remote := []byte("a\nc\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatalf("expected clean merge, got %d conflicts", len(r.Conflicts))
	}
	if string(r.Content) != "a\nb\nc\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayRemoteAddsLines(t *testing.T) {
	base := []byte("a\nc\n")
	local := []byte("a\nc\n")
	remote := []byte("a\nb\nc\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatal("expected clean merge")
	}
	if string(r.Content) != "a\nb\nc\n" {
		t.Fatalf("got %q", r.Content)
	}
}

func TestThreeWayEmptyBase(t *testing.T) {
	base := []byte("")
	local := []byte("same line\n")
	remote := []byte("different line\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	// Both added different content to empty base — conflict.
	// (Both sides insert at position 0, overlapping hunk.)
	if r.Clean {
		// If the algorithm treats both as non-overlapping inserts, that's
		// also acceptable for empty base — just verify both are present.
		if !strings.Contains(string(r.Content), "same line") || !strings.Contains(string(r.Content), "different line") {
			t.Fatalf("expected both additions, got %q", r.Content)
		}
	}
}

func TestThreeWayBothAddDifferentRegions(t *testing.T) {
	base := []byte("line1\nline2\nline3\nline4\nline5\n")
	local := []byte("LOCAL\nline1\nline2\nline3\nline4\nline5\n")
	remote := []byte("line1\nline2\nline3\nline4\nline5\nREMOTE\n")
	r, err := (&ThreeWayText{}).Merge(base, local, remote)
	if err != nil {
		t.Fatal(err)
	}
	if !r.Clean {
		t.Fatalf("expected clean merge (additions in different regions), got %d conflicts", len(r.Conflicts))
	}
	if !strings.Contains(string(r.Content), "LOCAL") {
		t.Fatal("missing local addition")
	}
	if !strings.Contains(string(r.Content), "REMOTE") {
		t.Fatal("missing remote addition")
	}
}