internal/postgres: reimplement alternative-module check

When inserting a module, we skip inserting into search_documents if
the module path is an alternative one.

This CL factors out that test, and also reimplements it in terms of
the latest cooked version.  Previously, any later version with a 491
status would classify the path as alternative, but this version uses
the latest cooked (non-retracted) version's status to decide, allowing
module authors to fix mistakes.

Change-Id: I3588f3df6a1a4dd4db59333314c34167eda51df1

For golang/go#44710

Change-Id: I670d9085800fed198e6dd6469f1a8d5728c5f039
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/303309
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/internal/postgres/insert_module_test.go b/internal/postgres/insert_module_test.go
index 367e2c87..48d2db74 100644
--- a/internal/postgres/insert_module_test.go
+++ b/internal/postgres/insert_module_test.go
@@ -507,6 +507,7 @@ func TestPostgres_NewerAlternative(t *testing.T) {
 		GoModPath:  "example.com/mod",
 		FetchErr:   derrors.AlternativeModule,
 	}
+	addLatest(ctx, t, testDB, mvs.ModulePath, altVersion, "")
 	if err := testDB.UpsertModuleVersionState(ctx, mvs); err != nil {
 		t.Fatal(err)
 	}
@@ -607,3 +608,46 @@ func TestLock(t *testing.T) {
 		t.Errorf("got %d, want %d", count, n)
 	}
 }
+
+func TestIsAlternativeModulePath(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+	testDB, release := acquire(t)
+	defer release()
+
+	const modulePath = "m.com/a"
+	altModuleStatus := derrors.ToStatus(derrors.AlternativeModule)
+	// These tests form a sequence. Each test's state affects the next's.
+	for _, test := range []struct {
+		version string
+		status  int
+		want    bool
+	}{
+		{"v1.2.0", 200, false},                 // no 491s
+		{"v1.1.0", altModuleStatus, false},     // 491 is earlier
+		{"v1.3.0-pre", altModuleStatus, false}, // still earlier: release beats pre-release
+		{"v1.3.0", altModuleStatus, true},      // latest version is 491
+		{"v1.4.0", 200, false},                 // new latest version is OK
+		{"v1.5.0", altModuleStatus, true},      // "I can do this all day." --Captain America
+	} {
+		addLatest(ctx, t, testDB, modulePath, test.version, "")
+		if err := testDB.UpsertModuleVersionState(ctx, &ModuleVersionStateForUpsert{
+			ModulePath: modulePath,
+			Version:    test.version,
+			AppVersion: "appVersion",
+			Timestamp:  time.Now(),
+			Status:     test.status,
+			HasGoMod:   true,
+		}); err != nil {
+			t.Fatal(err)
+		}
+
+		got, err := isAlternativeModulePath(ctx, testDB.db, modulePath)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got != test.want {
+			t.Fatalf("%q, %d: got %t, want %t", test.version, test.status, got, test.want)
+		}
+	}
+}