chore: Deprecate usage of ioutil package (sourcegraph#21796)

The package was deprecated in Go 1.16:
https://golang.org/doc/go1.16#ioutil

A CI check was also added so that we don't import it again in the future.

cmd/frontend/backend/go_importers.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"path"
 	"path/filepath"
@@ -93,7 +93,7 @@ func CountGoImporters(ctx context.Context, repo api.RepoName) (count int, err er
 				Path string
 			}
 		}
-		bytes, err := ioutil.ReadAll(response.Body)
+		bytes, err := io.ReadAll(response.Body)
 		if err != nil {
 			return 0, err
 		}

cmd/frontend/backend/go_importers_test.go

@@ -3,7 +3,8 @@ package backend
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
+	"io"
+	"io/fs"
 	"net/http"
 	"os"
 	"strings"
@@ -48,8 +49,8 @@ func TestCountGoImporters(t *testing.T) {
 	git.Mocks.ResolveRevision = func(spec string, opt git.ResolveRevisionOptions) (api.CommitID, error) {
 		return "c", nil
 	}
-	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]os.FileInfo, error) {
-		return []os.FileInfo{
+	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]fs.FileInfo, error) {
+		return []fs.FileInfo{
 			&util.FileInfo{Name_: "d/a.go", Mode_: os.ModeDir},
 			&util.FileInfo{Name_: "d/b.go", Mode_: os.ModeDir},
 			&util.FileInfo{Name_: "c.go", Mode_: 0},
@@ -80,7 +81,7 @@ type mockRoundTripper struct {
 func (t mockRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
 	return &http.Response{
 		StatusCode: http.StatusOK,
-		Body:       ioutil.NopCloser(bytes.NewBufferString(t.response)),
+		Body:       io.NopCloser(bytes.NewBufferString(t.response)),
 		Header:     make(http.Header),
 	}, nil
 }

cmd/frontend/backend/inventory.go

@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"os"
+	"io/fs"
 	"strconv"
 
 	"github.com/inconshreveable/log15"
@@ -31,23 +31,23 @@ func InventoryContext(repo api.RepoName, commitID api.CommitID, forceEnhancedLan
 		return inventory.Context{}, errors.Errorf("refusing to compute inventory for non-absolute commit ID %q", commitID)
 	}
 
-	cacheKey := func(e os.FileInfo) string {
+	cacheKey := func(e fs.FileInfo) string {
 		info, ok := e.Sys().(git.ObjectInfo)
 		if !ok {
 			return "" // not cacheable
 		}
 		return info.OID().String()
 	}
 	invCtx := inventory.Context{
-		ReadTree: func(ctx context.Context, path string) ([]os.FileInfo, error) {
+		ReadTree: func(ctx context.Context, path string) ([]fs.FileInfo, error) {
 			// TODO: As a perf optimization, we could read multiple levels of the Git tree at once
 			// to avoid sequential tree traversal calls.
 			return git.ReadDir(ctx, repo, commitID, path, false)
 		},
 		NewFileReader: func(ctx context.Context, path string) (io.ReadCloser, error) {
 			return git.NewFileReader(ctx, repo, commitID, path)
 		},
-		CacheGet: func(e os.FileInfo) (inventory.Inventory, bool) {
+		CacheGet: func(e fs.FileInfo) (inventory.Inventory, bool) {
 			cacheKey := cacheKey(e)
 			if cacheKey == "" {
 				return inventory.Inventory{}, false // not cacheable
@@ -62,7 +62,7 @@ func InventoryContext(repo api.RepoName, commitID api.CommitID, forceEnhancedLan
 			}
 			return inventory.Inventory{}, false
 		},
-		CacheSet: func(e os.FileInfo, inv inventory.Inventory) {
+		CacheSet: func(e fs.FileInfo, inv inventory.Inventory) {
 			cacheKey := cacheKey(e)
 			if cacheKey == "" {
 				return // not cacheable

cmd/frontend/backend/repos_test.go

@@ -5,7 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"io/fs"
 	"os"
 	"reflect"
 	"testing"
@@ -124,24 +124,24 @@ func TestReposGetInventory(t *testing.T) {
 		return &protocol.RepoLookupResult{Repo: &protocol.RepoInfo{Name: wantRepo}}, nil
 	}
 	defer func() { repoupdater.MockRepoLookup = nil }()
-	git.Mocks.Stat = func(commit api.CommitID, path string) (os.FileInfo, error) {
+	git.Mocks.Stat = func(commit api.CommitID, path string) (fs.FileInfo, error) {
 		if commit != wantCommitID {
 			t.Errorf("got commit %q, want %q", commit, wantCommitID)
 		}
 		return &util.FileInfo{Name_: path, Mode_: os.ModeDir, Sys_: gitObjectInfo(wantRootOID)}, nil
 	}
-	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]os.FileInfo, error) {
+	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]fs.FileInfo, error) {
 		if commit != wantCommitID {
 			t.Errorf("got commit %q, want %q", commit, wantCommitID)
 		}
 		switch name {
 		case "":
-			return []os.FileInfo{
+			return []fs.FileInfo{
 				&util.FileInfo{Name_: "a", Mode_: os.ModeDir, Sys_: gitObjectInfo("oid-a")},
 				&util.FileInfo{Name_: "b.go", Size_: 12},
 			}, nil
 		case "a":
-			return []os.FileInfo{&util.FileInfo{Name_: "a/c.m", Size_: 24}}, nil
+			return []fs.FileInfo{&util.FileInfo{Name_: "a/c.m", Size_: 24}}, nil
 		default:
 			panic("unhandled mock ReadDir " + name)
 		}
@@ -159,7 +159,7 @@ func TestReposGetInventory(t *testing.T) {
 		default:
 			panic("unhandled mock ReadFile " + name)
 		}
-		return ioutil.NopCloser(bytes.NewReader(data)), nil
+		return io.NopCloser(bytes.NewReader(data)), nil
 	}
 	defer git.ResetMocks()
 

cmd/frontend/graphqlbackend/git_tree.go

@@ -2,7 +2,7 @@ package graphqlbackend
 
 import (
 	"context"
-	"os"
+	"io/fs"
 	"path"
 	"sort"
 	"strings"
@@ -30,14 +30,14 @@ func (r *GitTreeEntryResolver) Entries(ctx context.Context, args *gitTreeEntryCo
 }
 
 func (r *GitTreeEntryResolver) Directories(ctx context.Context, args *gitTreeEntryConnectionArgs) ([]*GitTreeEntryResolver, error) {
-	return r.entries(ctx, args, func(fi os.FileInfo) bool { return fi.Mode().IsDir() })
+	return r.entries(ctx, args, func(fi fs.FileInfo) bool { return fi.Mode().IsDir() })
 }
 
 func (r *GitTreeEntryResolver) Files(ctx context.Context, args *gitTreeEntryConnectionArgs) ([]*GitTreeEntryResolver, error) {
-	return r.entries(ctx, args, func(fi os.FileInfo) bool { return !fi.Mode().IsDir() })
+	return r.entries(ctx, args, func(fi fs.FileInfo) bool { return !fi.Mode().IsDir() })
 }
 
-func (r *GitTreeEntryResolver) entries(ctx context.Context, args *gitTreeEntryConnectionArgs, filter func(fi os.FileInfo) bool) ([]*GitTreeEntryResolver, error) {
+func (r *GitTreeEntryResolver) entries(ctx context.Context, args *gitTreeEntryConnectionArgs, filter func(fi fs.FileInfo) bool) ([]*GitTreeEntryResolver, error) {
 	entries, err := git.ReadDir(
 		ctx,
 		r.commit.repoResolver.RepoName(),
@@ -83,7 +83,7 @@ func (r *GitTreeEntryResolver) entries(ctx context.Context, args *gitTreeEntryCo
 	return l, nil
 }
 
-type byDirectory []os.FileInfo
+type byDirectory []fs.FileInfo
 
 func (s byDirectory) Len() int {
 	return len(s)

cmd/frontend/graphqlbackend/git_tree_entry.go

@@ -2,6 +2,7 @@ package graphqlbackend
 
 import (
 	"context"
+	"io/fs"
 	"net/url"
 	neturl "net/url"
 	"os"
@@ -43,13 +44,13 @@ type GitTreeEntryResolver struct {
 
 	// stat is this tree entry's file info. Its Name method must return the full path relative to
 	// the root, not the basename.
-	stat os.FileInfo
+	stat fs.FileInfo
 
 	isRecursive   bool  // whether entries is populated recursively (otherwise just current level of hierarchy)
 	isSingleChild *bool // whether this is the single entry in its parent. Only set by the (&GitTreeEntryResolver) entries.
 }
 
-func NewGitTreeEntryResolver(commit *GitCommitResolver, db dbutil.DB, stat os.FileInfo) *GitTreeEntryResolver {
+func NewGitTreeEntryResolver(commit *GitCommitResolver, db dbutil.DB, stat fs.FileInfo) *GitTreeEntryResolver {
 	return &GitTreeEntryResolver{db: db, commit: commit, stat: stat}
 }
 
@@ -192,7 +193,7 @@ func cloneURLToRepoName(ctx context.Context, cloneURL string) (string, error) {
 	return string(repoName), nil
 }
 
-func CreateFileInfo(path string, isDir bool) os.FileInfo {
+func CreateFileInfo(path string, isDir bool) fs.FileInfo {
 	return fileInfo{path: path, isDir: isDir}
 }
 

cmd/frontend/graphqlbackend/git_tree_test.go

@@ -2,6 +2,7 @@ package graphqlbackend
 
 import (
 	"context"
+	"io/fs"
 	"os"
 	"testing"
 
@@ -29,7 +30,7 @@ func TestGitTree(t *testing.T) {
 	}
 	backend.Mocks.Repos.MockGetCommit_Return_NoCheck(t, &git.Commit{ID: exampleCommitSHA1})
 
-	git.Mocks.Stat = func(commit api.CommitID, path string) (os.FileInfo, error) {
+	git.Mocks.Stat = func(commit api.CommitID, path string) (fs.FileInfo, error) {
 		if string(commit) != exampleCommitSHA1 {
 			t.Errorf("got commit %q, want %q", commit, exampleCommitSHA1)
 		}
@@ -38,7 +39,7 @@ func TestGitTree(t *testing.T) {
 		}
 		return &util.FileInfo{Name_: path, Mode_: os.ModeDir}, nil
 	}
-	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]os.FileInfo, error) {
+	git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]fs.FileInfo, error) {
 		if string(commit) != exampleCommitSHA1 {
 			t.Errorf("got commit %q, want %q", commit, exampleCommitSHA1)
 		}
@@ -48,7 +49,7 @@ func TestGitTree(t *testing.T) {
 		if recurse {
 			t.Error("got recurse == false, want true")
 		}
-		return []os.FileInfo{
+		return []fs.FileInfo{
 			&util.FileInfo{Name_: name + "/testDirectory", Mode_: os.ModeDir},
 			&util.FileInfo{Name_: name + "/Geoffrey's random queries.32r242442bf", Mode_: os.ModeDir},
 			&util.FileInfo{Name_: name + "/testFile", Mode_: 0},

cmd/frontend/graphqlbackend/graphqlbackend_test.go

@@ -7,7 +7,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"os"
@@ -108,7 +108,7 @@ func TestMain(m *testing.M) {
 	flag.Parse()
 	if !testing.Verbose() {
 		log15.Root().SetHandler(log15.LvlFilterHandler(log15.LvlError, log15.Root().GetHandler()))
-		log.SetOutput(ioutil.Discard)
+		log.SetOutput(io.Discard)
 	}
 	os.Exit(m.Run())
 }
@@ -188,7 +188,7 @@ func TestAffiliatedRepositories(t *testing.T) {
 				}
 			}
 			return &http.Response{
-				Body:       ioutil.NopCloser(buf),
+				Body:       io.NopCloser(buf),
 				StatusCode: http.StatusOK,
 			}, nil
 		},
@@ -206,7 +206,7 @@ func TestAffiliatedRepositories(t *testing.T) {
 				t.Fatal(err)
 			}
 			return &http.Response{
-				Body:       ioutil.NopCloser(buf),
+				Body:       io.NopCloser(buf),
 				StatusCode: http.StatusOK,
 			}, nil
 		},

cmd/frontend/graphqlbackend/repository_comparison_test.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"html/template"
 	"io"
-	"io/ioutil"
 	"strings"
 	"testing"
 	"time"
@@ -49,7 +48,7 @@ func TestRepositoryComparison(t *testing.T) {
 		if len(args) < 1 && args[0] != "diff" {
 			t.Fatalf("gitserver.ExecReader received wrong args: %v", args)
 		}
-		return ioutil.NopCloser(strings.NewReader(testDiff + testCopyDiff)), nil
+		return io.NopCloser(strings.NewReader(testDiff + testCopyDiff)), nil
 	}
 	t.Cleanup(func() { git.Mocks.ExecReader = nil })
 

cmd/frontend/graphqlbackend/search_results_stats_languages.go

@@ -3,7 +3,7 @@ package graphqlbackend
 import (
 	"context"
 	"errors"
-	"os"
+	"io/fs"
 	"sync"
 
 	"github.com/neelance/parallel"
@@ -51,7 +51,7 @@ func searchResultsStatsLanguages(ctx context.Context, matches []result.Match) ([
 
 	// Records the work necessary for a batch (repoCommit).
 	type fileStatsWork struct {
-		fullEntries  []os.FileInfo     // matched these full files
+		fullEntries  []fs.FileInfo     // matched these full files
 		partialFiles map[string]uint64 // file with line matches (path) -> count of lines matching
 	}
 

cmd/frontend/graphqlbackend/search_results_stats_languages_test.go

@@ -4,8 +4,7 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"io/ioutil"
-	"os"
+	"io/fs"
 	"reflect"
 	"strings"
 	"testing"
@@ -35,7 +34,7 @@ func TestSearchResultsStatsLanguages(t *testing.T) {
 		default:
 			panic("unhandled mock NewFileReader " + name)
 		}
-		return ioutil.NopCloser(bytes.NewReader(data)), nil
+		return io.NopCloser(bytes.NewReader(data)), nil
 	}
 	const wantDefaultBranchRef = "refs/heads/foo"
 	git.Mocks.ExecSafe = func(params []string) (stdout, stderr []byte, exitCode int, err error) {
@@ -66,7 +65,7 @@ func TestSearchResultsStatsLanguages(t *testing.T) {
 
 	tests := map[string]struct {
 		results  []result.Match
-		getFiles []os.FileInfo
+		getFiles []fs.FileInfo
 		want     []inventory.Lang // TotalBytes values are incorrect (known issue doc'd in GraphQL schema)
 	}{
 		"empty": {
@@ -96,7 +95,7 @@ func TestSearchResultsStatsLanguages(t *testing.T) {
 			results: []result.Match{
 				&result.RepoMatch{Name: "r"},
 			},
-			getFiles: []os.FileInfo{
+			getFiles: []fs.FileInfo{
 				fileInfo{path: "two.go"},
 				fileInfo{path: "three.go"},
 			},
@@ -105,7 +104,7 @@ func TestSearchResultsStatsLanguages(t *testing.T) {
 	}
 	for name, test := range tests {
 		t.Run(name, func(t *testing.T) {
-			git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]os.FileInfo, error) {
+			git.Mocks.ReadDir = func(commit api.CommitID, name string, recurse bool) ([]fs.FileInfo, error) {
 				return test.getFiles, nil
 			}
 

cmd/frontend/graphqlbackend/set_external_service_repos_test.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"reflect"
 	"testing"
@@ -74,7 +74,7 @@ func TestSetExternalServiceRepos(t *testing.T) {
 		Transport: roundTripFunc(func(r *http.Request) (*http.Response, error) {
 			return &http.Response{
 				StatusCode: http.StatusOK,
-				Body:       ioutil.NopCloser(bytes.NewReader([]byte{})),
+				Body:       io.NopCloser(bytes.NewReader([]byte{})),
 			}, nil
 		}),
 	}