internal/task: change buildVSCGO to produce zip files

Signing service expects zip as input. Pack the binary in a zip file.
The file name is <randomnumber>-<platform>-vscgo.zip.

For golang/vscode-go#3186

Change-Id: I7d91dfbd2b5f0c4386421c2abfe77df254b392fb
Reviewed-on: https://go-review.googlesource.com/c/build/+/587735
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

internal/task/vscodego.go

@@ -5,6 +5,7 @@
 package task
 
 import (
+	"archive/zip"
 	"errors"
 	"fmt"
 	"io"
@@ -124,6 +125,9 @@ func (t *VSCodeGoReleaseTask) buildVSCGO(ctx *wf.TaskContext, version string) ([
 		})
 		return nil
 	})
+	if err != nil {
+		return nil, err
+	}
 
 	var eg errgroup.Group
 	for i := range artifacts {
@@ -136,14 +140,25 @@ func (t *VSCodeGoReleaseTask) buildVSCGO(ctx *wf.TaskContext, version string) ([
 				return err
 			}
 			defer in.Close()
-			name, out, err := t.ScratchFS.OpenWrite(ctx, platform+"-"+filepath.Base(path))
+			name, out, err := t.ScratchFS.OpenWrite(ctx, platform+"-vscgo.zip")
+			if err != nil {
+				out.Close()
+				return err
+			}
+			// write as zip file.
+			zw := zip.NewWriter(out)
+			f, err := zw.Create(filepath.Base(path))
 			if err != nil {
+				out.Close()
 				return err
 			}
-			if _, err := io.Copy(out, in); err != nil {
+			if _, err := io.Copy(f, in); err != nil {
 				out.Close()
 				return err
 			}
+			if err := zw.Close(); err != nil {
+				return err
+			}
 			if err := out.Close(); err != nil {
 				return err
 			}

internal/task/vscodego_test.go

@@ -5,10 +5,13 @@
 package task
 
 import (
+	"archive/zip"
 	"bytes"
 	"context"
-	"os"
+	"fmt"
+	"io"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -126,28 +129,74 @@ esac
 					Platform: p.Platform,
 				})
 			}
-			sortSlice := cmpopts.SortSlices(func(x, y goBuildArtifact) bool { return x.Platform < y.Platform })
+			sortSlice := cmpopts.SortSlices(
+				func(x, y goBuildArtifact) bool { return x.Platform < y.Platform },
+			)
 			ignoreFilename := cmpopts.IgnoreFields(goBuildArtifact{}, "Filename")
 			if diff := cmp.Diff(buildArtifacts, want, sortSlice, ignoreFilename); diff != "" {
 				t.Fatal(diff)
 			}
 			// HACK: Reading directly from the scratch filesystem.
-			// XXX: is there a better way??
 			envMap := make(map[string][]string)
 			for _, p := range vscgoPlatforms {
 				envMap[p.Platform] = p.Env
 			}
+			re := regexp.MustCompile(`-([a-z0-9]+-[a-z0-9]+)-vscgo\.zip$`)
 			for _, a := range buildArtifacts {
-				data, err := os.ReadFile(filepath.Join(scratchDir, w.ID.String(), a.Filename))
+				m := re.FindStringSubmatch(a.Filename)
+				if m == nil {
+					t.Errorf(
+						"artifact file with unexpected file name: %q, want <platform>-<arch>-vscgo.zip",
+						a.Filename,
+					)
+					continue
+				}
+				platform := m[1]
+				if platform != a.Platform {
+					t.Errorf(
+						"artifact file with unexpected platform: %q, want %q",
+						a.Platform,
+						platform,
+					)
+					continue
+				}
+				// The output files are zip files.
+				executable := "vscgo"
+				if strings.HasPrefix(platform, "win32") {
+					executable = "vscgo.exe"
+				}
+				data, err := extractFileZip(t, filepath.Join(scratchDir, w.ID.String(), a.Filename), executable)
 				if err != nil {
 					t.Errorf("%v: %v", a.Platform, err)
 				}
 				envs := envMap[a.Platform]
 				if !bytes.Contains(data, []byte(strings.Join(envs, " "))) {
 					t.Errorf("%v: unexpected contents: %s", a.Platform, data)
 				}
-
 			}
 		})
 	}
 }
+
+func extractFileZip(t *testing.T, zipfile, fileToExtract string) ([]byte, error) {
+	r, err := zip.OpenReader(zipfile)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Close()
+
+	// Iterate through the files in the archive,
+	// return the contents of the requested file.
+	for _, f := range r.File {
+		if f.Name != fileToExtract {
+			t.Errorf("unexpected file in zip: %q", f.Name)
+			continue
+		}
+		rc, err := f.Open()
+		if err != nil {
+			return nil, err
+		}
+		return io.ReadAll(rc)
+	}
+	return nil, fmt.Errorf("file %q not found", fileToExtract)
+}