internal/worker/fetcherror_test.go - pkgsite - Git at Google

 // Copyright 2019 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 package worker

 import (
 	"context"
 	"database/sql"
 	"errors"
 	"fmt"
 	"net/http"
 	"sort"
 	"strings"
 	"testing"

 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"golang.org/x/pkgsite/internal"
 	"golang.org/x/pkgsite/internal/derrors"
 	"golang.org/x/pkgsite/internal/fetch"
 	"golang.org/x/pkgsite/internal/godoc"
 	"golang.org/x/pkgsite/internal/postgres"
 	"golang.org/x/pkgsite/internal/proxy"
 	"golang.org/x/pkgsite/internal/proxy/proxytest"
 	"golang.org/x/pkgsite/internal/source"
 	"golang.org/x/pkgsite/internal/testing/sample"
 	"golang.org/x/pkgsite/internal/testing/testhelper"
 )

 // Check that when the proxy says it does not have module@version,
 // we delete it from the database.
 func TestFetchAndUpdateState_NotFound(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()
 	defer postgres.ResetTestDB(testDB, t)

 	proxyClient, teardown := proxytest.SetupTestClient(t, []*proxytest.Module{
 		{
 			ModulePath: sample.ModulePath,
 			Version:    sample.VersionString,
 			Files: map[string]string{
 				"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
 				"README.md":  "This is a readme",
 				"LICENSE":    testhelper.MITLicense,
 			},
 		},
 	})
 	defer teardown()
 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusOK)

 	// Take down the module, by having the proxy serve a 404/410 for it.
 	proxyServer := proxytest.NewServer([]*proxytest.Module{})
 	proxyServer.AddRoute(
 		fmt.Sprintf("/%s/@v/%s.info", sample.ModulePath, sample.VersionString),
 		func(w http.ResponseWriter, r *http.Request) { http.Error(w, "taken down", http.StatusGone) })
 	proxyClient, teardownProxy2, err := proxytest.NewClientForServer(proxyServer)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer teardownProxy2()

 	// Now fetch it again. The new state should have a status of Not Found.
 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusNotFound)
 	checkPackageVersionStates(ctx, t, sample.ModulePath, sample.VersionString, []*internal.PackageVersionState{
 		{
 			PackagePath: sample.ModulePath + "/foo",
 			ModulePath:  sample.ModulePath,
 			Version:     sample.VersionString,
 			Status:      http.StatusOK,
 		},
 	})

 	// The module should no longer be in the database:
 	// - It shouldn't be in the modules table. That also covers licenses, packages and paths tables
 	//   via foreign key constraints with ON DELETE CASCADE.
 	// - It shouldn't be in other tables like search_documents and the various imports tables.
 	if _, err := testDB.GetModuleInfo(ctx, sample.ModulePath, sample.VersionString); !errors.Is(err, derrors.NotFound) {
 		t.Fatalf("GetModuleInfo: got %v, want NotFound", err)
 	}
 	checkNotInTable := func(table, column string) {
 		q := fmt.Sprintf("SELECT 1 FROM %s WHERE %s = $1 LIMIT 1", table, column)
 		var x int
 		err := testDB.Underlying().QueryRow(ctx, q, sample.ModulePath).Scan(&x)
 		if err != sql.ErrNoRows {
 			t.Errorf("table %s: got %v, want ErrNoRows", table, err)
 		}
 	}
 	checkNotInTable("search_documents", "module_path")
 	checkNotInTable("imports_unique", "from_module_path")
 }

 func TestFetchAndUpdateState_Excluded(t *testing.T) {
 	// Check that an excluded module is not processed, and is marked excluded in module_version_states.
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	defer postgres.ResetTestDB(testDB, t)

 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, nil)
 	defer teardownProxy()

 	if err := testDB.InsertExcludedPrefix(ctx, sample.ModulePath, "user", "for testing"); err != nil {
 		t.Fatal(err)
 	}

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusForbidden)
 }

 func TestFetchAndUpdateState_BadRequestedVersion(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	defer postgres.ResetTestDB(testDB, t)
 	var (
 		modulePath = buildConstraintsModulePath
 		version    = "badversion"
 	)
 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, testModules)
 	defer teardownProxy()
 	fetchAndCheckStatus(ctx, t, proxyClient, modulePath, version, http.StatusNotFound)
 }

 func TestFetchAndUpdateState_Incomplete(t *testing.T) {
 	// Check that we store the special "incomplete" status in module_version_states.
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	defer postgres.ResetTestDB(testDB, t)

 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, testModules)
 	defer teardownProxy()

 	fetchAndCheckStatus(ctx, t, proxyClient, buildConstraintsModulePath, buildConstraintsVersion, hasIncompletePackagesCode)
 	checkPackageVersionStates(ctx, t, buildConstraintsModulePath, buildConstraintsVersion, []*internal.PackageVersionState{
 		{
 			PackagePath: buildConstraintsModulePath + "/cpu",
 			ModulePath:  buildConstraintsModulePath,
 			Version:     buildConstraintsVersion,
 			Status:      200,
 		},
 		{
 			PackagePath: buildConstraintsModulePath + "/ignore",
 			ModulePath:  buildConstraintsModulePath,
 			Version:     buildConstraintsVersion,
 			Status:      600,
 		},
 	})
 }

 func TestFetchAndUpdateState_Mismatch(t *testing.T) {
 	// Check that an excluded module is not processed, and is marked excluded in module_version_states.
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	defer postgres.ResetTestDB(testDB, t)

 	const goModPath = "other"
 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
 		{
 			ModulePath: sample.ModulePath,
 			Version:    sample.VersionString,
 			Files: map[string]string{
 				"go.mod":     "module " + goModPath,
 				"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
 			},
 		},
 	})
 	defer teardownProxy()

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString,
 		derrors.ToStatus(derrors.AlternativeModule))
 }

 func TestFetchAndUpdateState_DeleteOlder(t *testing.T) {
 	// Check that fetching an alternative module deletes all older versions of that
 	// module from search_documents (but not versions).
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()

 	defer postgres.ResetTestDB(testDB, t)

 	const (
 		mismatchVersion = "v1.0.0"
 		olderVersion    = "v0.9.0"
 	)

 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
 		{
 			// mismatched version; will cause deletion
 			ModulePath: sample.ModulePath,
 			Version:    mismatchVersion,
 			Files: map[string]string{
 				"go.mod":     "module other",
 				"foo/foo.go": "package foo",
 			},
 		},
 		{
 			// older version; should be deleted
 			ModulePath: sample.ModulePath,
 			Version:    olderVersion,
 			Files: map[string]string{
 				"foo/foo.go": "package foo",
 			},
 		},
 	})
 	defer teardownProxy()

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, olderVersion, http.StatusOK)
 	gotModule, gotVersion, gotFound := postgres.GetFromSearchDocuments(ctx, t, testDB, sample.ModulePath+"/foo")
 	if !gotFound || gotModule != sample.ModulePath || gotVersion != olderVersion {
 		t.Fatalf("got (%q, %q, %t), want (%q, %q, true)", gotModule, gotVersion, gotFound, sample.ModulePath, olderVersion)
 	}

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, mismatchVersion, derrors.ToStatus(derrors.AlternativeModule))
 	if _, _, gotFound := postgres.GetFromSearchDocuments(ctx, t, testDB, sample.ModulePath+"/foo"); gotFound {
 		t.Fatal("older version found in search documents")
 	}
 }

 func TestFetchAndUpdateState_SkipIncompletePackage(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()
 	defer postgres.ResetTestDB(testDB, t)
 	badModule := map[string]string{
 		"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
 		"README.md":  "This is a readme",
 		"LICENSE":    testhelper.MITLicense,
 	}
 	var bigFile strings.Builder
 	bigFile.WriteString("package bar\n")
 	bigFile.WriteString("const Bar = 123\n")
 	for bigFile.Len() <= fetch.MaxFileSize {
 		bigFile.WriteString("// All work and no play makes Jack a dull boy.\n")
 	}
 	badModule["bar/bar.go"] = bigFile.String()
 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
 		{
 			ModulePath: sample.ModulePath,
 			Version:    sample.VersionString,
 			Files:      badModule,
 		},
 	})
 	defer teardownProxy()
 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, hasIncompletePackagesCode)
 	checkPackage(ctx, t, sample.ModulePath+"/foo")
 	if _, err := testDB.GetUnitMeta(ctx, sample.ModulePath+"/bar", internal.UnknownModulePath, sample.VersionString); !errors.Is(err, derrors.NotFound) {
 		t.Errorf("got %v, want NotFound", err)
 	}
 }

 func TestFetchAndUpdateState_Timeout(t *testing.T) {
 	defer postgres.ResetTestDB(testDB, t)

 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, nil)
 	defer teardownProxy()

 	ctx, cancel := context.WithTimeout(context.Background(), 0)
 	defer cancel()
 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusInternalServerError)
 }

 // Check that when the proxy says fetch timed out, we return a 5xx error so
 // that we automatically try to fetch it again later.
 func TestFetchAndUpdateState_ProxyTimedOut(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
 	defer cancel()
 	defer postgres.ResetTestDB(testDB, t)

 	proxyServer := proxytest.NewServer(nil)
 	proxyServer.AddRoute(
 		fmt.Sprintf("/%s/@v/%s.info", sample.ModulePath, sample.VersionString),
 		func(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "not found: fetch timed out", http.StatusNotFound)
 		})
 	proxyClient, teardownProxy, err := proxytest.NewClientForServer(proxyServer)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer teardownProxy()

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, derrors.ToStatus(derrors.ProxyTimedOut))
 }

 // Test that large string literals and slices are trimmed when
 // rendering documentation, rather than being included verbatim.
 //
 // This makes it viable for us to show documentation for packages that
 // would otherwise exceed HTML size limit and not get shown at all.
 func TestTrimLargeCode(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), testTimeout*3)
 	defer cancel()
 	defer postgres.ResetTestDB(testDB, t)
 	trimmedModule := map[string]string{
 		"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
 		"LICENSE":    testhelper.MITLicense,
 	}
 	// Create a package with a large string literal. It should not be included verbatim.
 	{
 		var b strings.Builder
 		b.WriteString("package bar\n\n")
 		b.WriteString("const Bar = `\n")
 		for b.Len() <= godoc.MaxDocumentationHTML {
 			b.WriteString("All work and no play makes Jack a dull boy.\n")
 		}
 		b.WriteString("`\n")
 		trimmedModule["bar/bar.go"] = b.String()
 	}
 	// Create a package with a large slice. It should not be included verbatim.
 	{
 		var b strings.Builder
 		b.WriteString("package baz\n\n")
 		b.WriteString("var Baz = []string{\n")
 		for b.Len() <= godoc.MaxDocumentationHTML {
 			b.WriteString("`All work and no play makes Jack a dull boy.`,\n")
 		}
 		b.WriteString("}\n")
 		trimmedModule["baz/baz.go"] = b.String()
 	}
 	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
 		{
 			ModulePath: sample.ModulePath,
 			Version:    sample.VersionString,
 			Files:      trimmedModule,
 		},
 	})
 	defer teardownProxy()

 	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusOK)
 	checkPackage(ctx, t, sample.ModulePath+"/foo")
 	checkPackage(ctx, t, sample.ModulePath+"/bar")
 	checkPackage(ctx, t, sample.ModulePath+"/baz")
 }

 func fetchAndCheckStatus(ctx context.Context, t *testing.T, proxyClient *proxy.Client, modulePath, version string, wantCode int) {
 	t.Helper()
 	f := Fetcher{proxyClient, source.NewClient(sourceTimeout), testDB, nil, nil, ""}
 	code, _, err := f.FetchAndUpdateState(ctx, modulePath, version, testAppVersion)
 	switch code {
 	case http.StatusOK:
 		if err != nil {
 			t.Fatalf("FetchAndUpdateState: %v", err)
 		}
 	case derrors.ToStatus(derrors.AlternativeModule):
 		if !errors.Is(err, derrors.AlternativeModule) {
 			t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.AlternativeModule)
 		}
 	case http.StatusNotFound:
 		if !errors.Is(err, derrors.NotFound) {
 			t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.NotFound)
 		}
 	case http.StatusForbidden:
 		if !errors.Is(err, derrors.Excluded) {
 			t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.NotFound)
 		}
 	case http.StatusInternalServerError:
 		// The only case where we check for a status 500 is in
 		// TestFetchAndUpdateState_Timeout.
 		wantErrString := "deadline exceeded"
 		if !strings.Contains(err.Error(), wantErrString) {
 			t.Fatalf("FetchAndUpdateState: %v; want error containing %q", err, wantErrString)
 		}
 		return
 	}
 	if code != wantCode {
 		t.Fatalf("got %d; want = %d", code, wantCode)
 	}

 	_, err = testDB.GetModuleInfo(ctx, modulePath, version)
 	switch code {
 	case http.StatusOK, hasIncompletePackagesCode:
 		if err != nil {
 			t.Fatalf("testDB.GetModuleInfo: %v", err)
 		}
 	default:
 		if !errors.Is(err, derrors.NotFound) {
 			t.Fatalf("GetModuleInfo: got %v, want Is(NotFound)", err)
 		}
 	}
 	vm, err := testDB.GetVersionMap(ctx, modulePath, version)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if vm.Status != wantCode {
 		t.Fatalf("testDB.GetVersionMap(ctx, %q, %q): status = %d, want = %d", modulePath, version, vm.Status, wantCode)
 	}
 }

 func checkPackageVersionStates(ctx context.Context, t *testing.T, modulePath, version string, wantStates []*internal.PackageVersionState) {
 	t.Helper()
 	gotStates, err := testDB.GetPackageVersionStatesForModule(ctx, modulePath, version)
 	if err != nil {
 		t.Fatal(err)
 	}
 	sort.Slice(gotStates, func(i, j int) bool {
 		return gotStates[i].PackagePath < gotStates[j].PackagePath
 	})
 	if diff := cmp.Diff(wantStates, gotStates, cmpopts.EquateEmpty()); diff != "" {
 		t.Errorf("testDB.GetPackageVersionStatesForModule(ctx, %q, %q) mismatch (-want +got):\n%s",
 			modulePath, version, diff)
 	}
 }

 func checkPackage(ctx context.Context, t *testing.T, pkgPath string) {
 	t.Helper()
 	if _, err := testDB.GetUnitMeta(ctx, pkgPath, internal.UnknownModulePath, sample.VersionString); err != nil {
 		t.Fatal(err)
 	}
 	um, err := testDB.GetUnitMeta(ctx, pkgPath, internal.UnknownModulePath, sample.VersionString)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if !um.IsPackage() {
 		t.Fatalf("testDB.GetUnitMeta(%q, %q, %q): isPackage = false; want = true",
 			pkgPath, internal.UnknownModulePath, sample.VersionString)
 	}
 	dir, err := testDB.GetUnit(ctx, um, internal.WithMain, internal.BuildContext{})
 	if err != nil {
 		t.Fatal(err)
 	}
 	if dir.Documentation == nil {
 		t.Fatalf("testDB.GetUnit(%q, %q, %q): documentation should not be nil",
 			um.Path, um.ModulePath, um.Version)
 	}
 }
	// Copyright 2019 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	package worker

	import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"net/http"
	"sort"
	"strings"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/derrors"
	"golang.org/x/pkgsite/internal/fetch"
	"golang.org/x/pkgsite/internal/godoc"
	"golang.org/x/pkgsite/internal/postgres"
	"golang.org/x/pkgsite/internal/proxy"
	"golang.org/x/pkgsite/internal/proxy/proxytest"
	"golang.org/x/pkgsite/internal/source"
	"golang.org/x/pkgsite/internal/testing/sample"
	"golang.org/x/pkgsite/internal/testing/testhelper"
	)

	// Check that when the proxy says it does not have module@version,
	// we delete it from the database.
	func TestFetchAndUpdateState_NotFound(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()
	defer postgres.ResetTestDB(testDB, t)

	proxyClient, teardown := proxytest.SetupTestClient(t, []*proxytest.Module{
	{
	ModulePath: sample.ModulePath,
	Version: sample.VersionString,
	Files: map[string]string{
	"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
	"README.md": "This is a readme",
	"LICENSE": testhelper.MITLicense,
	},
	},
	})
	defer teardown()
	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusOK)

	// Take down the module, by having the proxy serve a 404/410 for it.
	proxyServer := proxytest.NewServer([]*proxytest.Module{})
	proxyServer.AddRoute(
	fmt.Sprintf("/%s/@v/%s.info", sample.ModulePath, sample.VersionString),
	func(w http.ResponseWriter, r *http.Request) { http.Error(w, "taken down", http.StatusGone) })
	proxyClient, teardownProxy2, err := proxytest.NewClientForServer(proxyServer)
	if err != nil {
	t.Fatal(err)
	}
	defer teardownProxy2()

	// Now fetch it again. The new state should have a status of Not Found.
	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusNotFound)
	checkPackageVersionStates(ctx, t, sample.ModulePath, sample.VersionString, []*internal.PackageVersionState{
	{
	PackagePath: sample.ModulePath + "/foo",
	ModulePath: sample.ModulePath,
	Version: sample.VersionString,
	Status: http.StatusOK,
	},
	})

	// The module should no longer be in the database:
	// - It shouldn't be in the modules table. That also covers licenses, packages and paths tables
	// via foreign key constraints with ON DELETE CASCADE.
	// - It shouldn't be in other tables like search_documents and the various imports tables.
	if _, err := testDB.GetModuleInfo(ctx, sample.ModulePath, sample.VersionString); !errors.Is(err, derrors.NotFound) {
	t.Fatalf("GetModuleInfo: got %v, want NotFound", err)
	}
	checkNotInTable := func(table, column string) {
	q := fmt.Sprintf("SELECT 1 FROM %s WHERE %s = $1 LIMIT 1", table, column)
	var x int
	err := testDB.Underlying().QueryRow(ctx, q, sample.ModulePath).Scan(&x)
	if err != sql.ErrNoRows {
	t.Errorf("table %s: got %v, want ErrNoRows", table, err)
	}
	}
	checkNotInTable("search_documents", "module_path")
	checkNotInTable("imports_unique", "from_module_path")
	}

	func TestFetchAndUpdateState_Excluded(t *testing.T) {
	// Check that an excluded module is not processed, and is marked excluded in module_version_states.
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	defer postgres.ResetTestDB(testDB, t)

	proxyClient, teardownProxy := proxytest.SetupTestClient(t, nil)
	defer teardownProxy()

	if err := testDB.InsertExcludedPrefix(ctx, sample.ModulePath, "user", "for testing"); err != nil {
	t.Fatal(err)
	}

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusForbidden)
	}

	func TestFetchAndUpdateState_BadRequestedVersion(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	defer postgres.ResetTestDB(testDB, t)
	var (
	modulePath = buildConstraintsModulePath
	version = "badversion"
	)
	proxyClient, teardownProxy := proxytest.SetupTestClient(t, testModules)
	defer teardownProxy()
	fetchAndCheckStatus(ctx, t, proxyClient, modulePath, version, http.StatusNotFound)
	}

	func TestFetchAndUpdateState_Incomplete(t *testing.T) {
	// Check that we store the special "incomplete" status in module_version_states.
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	defer postgres.ResetTestDB(testDB, t)

	proxyClient, teardownProxy := proxytest.SetupTestClient(t, testModules)
	defer teardownProxy()

	fetchAndCheckStatus(ctx, t, proxyClient, buildConstraintsModulePath, buildConstraintsVersion, hasIncompletePackagesCode)
	checkPackageVersionStates(ctx, t, buildConstraintsModulePath, buildConstraintsVersion, []*internal.PackageVersionState{
	{
	PackagePath: buildConstraintsModulePath + "/cpu",
	ModulePath: buildConstraintsModulePath,
	Version: buildConstraintsVersion,
	Status: 200,
	},
	{
	PackagePath: buildConstraintsModulePath + "/ignore",
	ModulePath: buildConstraintsModulePath,
	Version: buildConstraintsVersion,
	Status: 600,
	},
	})
	}

	func TestFetchAndUpdateState_Mismatch(t *testing.T) {
	// Check that an excluded module is not processed, and is marked excluded in module_version_states.
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	defer postgres.ResetTestDB(testDB, t)

	const goModPath = "other"
	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
	{
	ModulePath: sample.ModulePath,
	Version: sample.VersionString,
	Files: map[string]string{
	"go.mod": "module " + goModPath,
	"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
	},
	},
	})
	defer teardownProxy()

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString,
	derrors.ToStatus(derrors.AlternativeModule))
	}

	func TestFetchAndUpdateState_DeleteOlder(t *testing.T) {
	// Check that fetching an alternative module deletes all older versions of that
	// module from search_documents (but not versions).
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()

	defer postgres.ResetTestDB(testDB, t)

	const (
	mismatchVersion = "v1.0.0"
	olderVersion = "v0.9.0"
	)

	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
	{
	// mismatched version; will cause deletion
	ModulePath: sample.ModulePath,
	Version: mismatchVersion,
	Files: map[string]string{
	"go.mod": "module other",
	"foo/foo.go": "package foo",
	},
	},
	{
	// older version; should be deleted
	ModulePath: sample.ModulePath,
	Version: olderVersion,
	Files: map[string]string{
	"foo/foo.go": "package foo",
	},
	},
	})
	defer teardownProxy()

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, olderVersion, http.StatusOK)
	gotModule, gotVersion, gotFound := postgres.GetFromSearchDocuments(ctx, t, testDB, sample.ModulePath+"/foo")
	if !gotFound \|\| gotModule != sample.ModulePath \|\| gotVersion != olderVersion {
	t.Fatalf("got (%q, %q, %t), want (%q, %q, true)", gotModule, gotVersion, gotFound, sample.ModulePath, olderVersion)
	}

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, mismatchVersion, derrors.ToStatus(derrors.AlternativeModule))
	if _, _, gotFound := postgres.GetFromSearchDocuments(ctx, t, testDB, sample.ModulePath+"/foo"); gotFound {
	t.Fatal("older version found in search documents")
	}
	}

	func TestFetchAndUpdateState_SkipIncompletePackage(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()
	defer postgres.ResetTestDB(testDB, t)
	badModule := map[string]string{
	"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
	"README.md": "This is a readme",
	"LICENSE": testhelper.MITLicense,
	}
	var bigFile strings.Builder
	bigFile.WriteString("package bar\n")
	bigFile.WriteString("const Bar = 123\n")
	for bigFile.Len() <= fetch.MaxFileSize {
	bigFile.WriteString("// All work and no play makes Jack a dull boy.\n")
	}
	badModule["bar/bar.go"] = bigFile.String()
	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
	{
	ModulePath: sample.ModulePath,
	Version: sample.VersionString,
	Files: badModule,
	},
	})
	defer teardownProxy()
	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, hasIncompletePackagesCode)
	checkPackage(ctx, t, sample.ModulePath+"/foo")
	if _, err := testDB.GetUnitMeta(ctx, sample.ModulePath+"/bar", internal.UnknownModulePath, sample.VersionString); !errors.Is(err, derrors.NotFound) {
	t.Errorf("got %v, want NotFound", err)
	}
	}

	func TestFetchAndUpdateState_Timeout(t *testing.T) {
	defer postgres.ResetTestDB(testDB, t)

	proxyClient, teardownProxy := proxytest.SetupTestClient(t, nil)
	defer teardownProxy()

	ctx, cancel := context.WithTimeout(context.Background(), 0)
	defer cancel()
	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusInternalServerError)
	}

	// Check that when the proxy says fetch timed out, we return a 5xx error so
	// that we automatically try to fetch it again later.
	func TestFetchAndUpdateState_ProxyTimedOut(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
	defer cancel()
	defer postgres.ResetTestDB(testDB, t)

	proxyServer := proxytest.NewServer(nil)
	proxyServer.AddRoute(
	fmt.Sprintf("/%s/@v/%s.info", sample.ModulePath, sample.VersionString),
	func(w http.ResponseWriter, r *http.Request) {
	http.Error(w, "not found: fetch timed out", http.StatusNotFound)
	})
	proxyClient, teardownProxy, err := proxytest.NewClientForServer(proxyServer)
	if err != nil {
	t.Fatal(err)
	}
	defer teardownProxy()

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, derrors.ToStatus(derrors.ProxyTimedOut))
	}

	// Test that large string literals and slices are trimmed when
	// rendering documentation, rather than being included verbatim.
	//
	// This makes it viable for us to show documentation for packages that
	// would otherwise exceed HTML size limit and not get shown at all.
	func TestTrimLargeCode(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), testTimeout*3)
	defer cancel()
	defer postgres.ResetTestDB(testDB, t)
	trimmedModule := map[string]string{
	"foo/foo.go": "// Package foo\npackage foo\n\nconst Foo = 42",
	"LICENSE": testhelper.MITLicense,
	}
	// Create a package with a large string literal. It should not be included verbatim.
	{
	var b strings.Builder
	b.WriteString("package bar\n\n")
	b.WriteString("const Bar = `\n")
	for b.Len() <= godoc.MaxDocumentationHTML {
	b.WriteString("All work and no play makes Jack a dull boy.\n")
	}
	b.WriteString("`\n")
	trimmedModule["bar/bar.go"] = b.String()
	}
	// Create a package with a large slice. It should not be included verbatim.
	{
	var b strings.Builder
	b.WriteString("package baz\n\n")
	b.WriteString("var Baz = []string{\n")
	for b.Len() <= godoc.MaxDocumentationHTML {
	b.WriteString("`All work and no play makes Jack a dull boy.`,\n")
	}
	b.WriteString("}\n")
	trimmedModule["baz/baz.go"] = b.String()
	}
	proxyClient, teardownProxy := proxytest.SetupTestClient(t, []*proxytest.Module{
	{
	ModulePath: sample.ModulePath,
	Version: sample.VersionString,
	Files: trimmedModule,
	},
	})
	defer teardownProxy()

	fetchAndCheckStatus(ctx, t, proxyClient, sample.ModulePath, sample.VersionString, http.StatusOK)
	checkPackage(ctx, t, sample.ModulePath+"/foo")
	checkPackage(ctx, t, sample.ModulePath+"/bar")
	checkPackage(ctx, t, sample.ModulePath+"/baz")
	}

	func fetchAndCheckStatus(ctx context.Context, t testing.T, proxyClient proxy.Client, modulePath, version string, wantCode int) {
	t.Helper()
	f := Fetcher{proxyClient, source.NewClient(sourceTimeout), testDB, nil, nil, ""}
	code, _, err := f.FetchAndUpdateState(ctx, modulePath, version, testAppVersion)
	switch code {
	case http.StatusOK:
	if err != nil {
	t.Fatalf("FetchAndUpdateState: %v", err)
	}
	case derrors.ToStatus(derrors.AlternativeModule):
	if !errors.Is(err, derrors.AlternativeModule) {
	t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.AlternativeModule)
	}
	case http.StatusNotFound:
	if !errors.Is(err, derrors.NotFound) {
	t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.NotFound)
	}
	case http.StatusForbidden:
	if !errors.Is(err, derrors.Excluded) {
	t.Fatalf("FetchAndUpdateState: %v; want = %v", err, derrors.NotFound)
	}
	case http.StatusInternalServerError:
	// The only case where we check for a status 500 is in
	// TestFetchAndUpdateState_Timeout.
	wantErrString := "deadline exceeded"
	if !strings.Contains(err.Error(), wantErrString) {
	t.Fatalf("FetchAndUpdateState: %v; want error containing %q", err, wantErrString)
	}
	return
	}
	if code != wantCode {
	t.Fatalf("got %d; want = %d", code, wantCode)
	}

	_, err = testDB.GetModuleInfo(ctx, modulePath, version)
	switch code {
	case http.StatusOK, hasIncompletePackagesCode:
	if err != nil {
	t.Fatalf("testDB.GetModuleInfo: %v", err)
	}
	default:
	if !errors.Is(err, derrors.NotFound) {
	t.Fatalf("GetModuleInfo: got %v, want Is(NotFound)", err)
	}
	}
	vm, err := testDB.GetVersionMap(ctx, modulePath, version)
	if err != nil {
	t.Fatal(err)
	}
	if vm.Status != wantCode {
	t.Fatalf("testDB.GetVersionMap(ctx, %q, %q): status = %d, want = %d", modulePath, version, vm.Status, wantCode)
	}
	}

	func checkPackageVersionStates(ctx context.Context, t testing.T, modulePath, version string, wantStates []internal.PackageVersionState) {
	t.Helper()
	gotStates, err := testDB.GetPackageVersionStatesForModule(ctx, modulePath, version)
	if err != nil {
	t.Fatal(err)
	}
	sort.Slice(gotStates, func(i, j int) bool {
	return gotStates[i].PackagePath < gotStates[j].PackagePath
	})
	if diff := cmp.Diff(wantStates, gotStates, cmpopts.EquateEmpty()); diff != "" {
	t.Errorf("testDB.GetPackageVersionStatesForModule(ctx, %q, %q) mismatch (-want +got):\n%s",
	modulePath, version, diff)
	}
	}

	func checkPackage(ctx context.Context, t *testing.T, pkgPath string) {
	t.Helper()
	if _, err := testDB.GetUnitMeta(ctx, pkgPath, internal.UnknownModulePath, sample.VersionString); err != nil {
	t.Fatal(err)
	}
	um, err := testDB.GetUnitMeta(ctx, pkgPath, internal.UnknownModulePath, sample.VersionString)
	if err != nil {
	t.Fatal(err)
	}
	if !um.IsPackage() {
	t.Fatalf("testDB.GetUnitMeta(%q, %q, %q): isPackage = false; want = true",
	pkgPath, internal.UnknownModulePath, sample.VersionString)
	}
	dir, err := testDB.GetUnit(ctx, um, internal.WithMain, internal.BuildContext{})
	if err != nil {
	t.Fatal(err)
	}
	if dir.Documentation == nil {
	t.Fatalf("testDB.GetUnit(%q, %q, %q): documentation should not be nil",
	um.Path, um.ModulePath, um.Version)
	}
	}