internal/coverage: refactor EmitTextual in preparation for bugfix

Refactor cformat.EmitTextual to accept a package filter (list of
packages to report). This is a no-op in terms of exposed coverage
functionality, but we will need this feature in a subsequent patch.

Updates #70244.

Change-Id: I1e6bcbfb5e68187d4d69d54b667e97bc1fdfa2d4
Reviewed-on: https://go-review.googlesource.com/c/go/+/627315
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/cmd/covdata/dump.go b/src/cmd/covdata/dump.go
index cbbeae0a8020de30b016ceed9266e67cb8042d23..e141689b00e563a48556efb5d68ac00efb9b1aa5 100644 (file)
--- a/src/cmd/covdata/dump.go
+++ b/src/cmd/covdata/dump.go
@@ -331,7 +331,7 @@ func (d *dstate) Finish() {
                        d.format.EmitFuncs(os.Stdout)
                }
                if d.textfmtoutf != nil {
-                       if err := d.format.EmitTextual(d.textfmtoutf); err != nil {
+                       if err := d.format.EmitTextual(nil, d.textfmtoutf); err != nil {
                                fatal("writing to %s: %v", *textfmtoutflag, err)
                        }
                }

diff --git a/src/internal/coverage/cfile/testsupport.go b/src/internal/coverage/cfile/testsupport.go
index 3594b32aee1a8df4bb740c2c05be9a21eedfd4af..56b39c5859a96bf58ae702d2f33083bc7b90db1b 100644 (file)
--- a/src/internal/coverage/cfile/testsupport.go
+++ b/src/internal/coverage/cfile/testsupport.go
@@ -109,7 +109,7 @@ func ProcessCoverTestDir(dir string, cfile string, cm string, cpkg string, w io.
 
        // Emit text output.
        if tf != nil {
-               if err := ts.cf.EmitTextual(tf); err != nil {
+               if err := ts.cf.EmitTextual(nil, tf); err != nil {
                        return err
                }
                tfClosed = true

diff --git a/src/internal/coverage/cformat/fmt_test.go b/src/internal/coverage/cformat/fmt_test.go
index d296939d5cd20ca6cc31f3b0cc81f53ee8ebe652..a26de964c435383ad54ec6a9245bd652f6a65c09 100644 (file)
--- a/src/internal/coverage/cformat/fmt_test.go
+++ b/src/internal/coverage/cformat/fmt_test.go
@@ -47,8 +47,8 @@ func TestBasics(t *testing.T) {
                fm.AddUnit("lit.go", "f3", true, u, 0)
        }
 
-       var b1, b2, b3, b4 strings.Builder
-       if err := fm.EmitTextual(&b1); err != nil {
+       var b1, b2, b3, b4, b5 strings.Builder
+       if err := fm.EmitTextual(nil, &b1); err != nil {
                t.Fatalf("EmitTextual returned %v", err)
        }
        wantText := strings.TrimSpace(`
@@ -64,6 +64,18 @@ lit.go:99.0,100.0 1 0`)
                t.Errorf("emit text: got:\n%s\nwant:\n%s\n", gotText, wantText)
        }
 
+       selected := []string{"my/pack2"}
+       if err := fm.EmitTextual(selected, &b5); err != nil {
+               t.Fatalf("EmitTextual returned %v", err)
+       }
+       wantText = strings.TrimSpace(`
+mode: atomic
+lit.go:99.0,100.0 1 0`)
+       gotText = strings.TrimSpace(b5.String())
+       if wantText != gotText {
+               t.Errorf("emit text: got:\n%s\nwant:\n%s\n", gotText, wantText)
+       }
+
        // Percent output with no aggregation.
        noCoverPkg := ""
        if err := fm.EmitPercent(&b2, nil, noCoverPkg, false, false); err != nil {

diff --git a/src/internal/coverage/cformat/format.go b/src/internal/coverage/cformat/format.go
index 4df0e70b81ca6e34232775f126cb8b73f04d68c2..01d3109e31fd9d1b737bd5ce0fd6bed28548ac73 100644 (file)
--- a/src/internal/coverage/cformat/format.go
+++ b/src/internal/coverage/cformat/format.go
@@ -24,7 +24,7 @@ package cformat
 //                     }
 //             }
 //             myformatter.EmitPercent(os.Stdout, nil, "", true, true)
-//             myformatter.EmitTextual(somefile)
+//             myformatter.EmitTextual(nil, somefile)
 //
 // These apis are linked into tests that are built with "-cover", and
 // called at the end of test execution to produce text output or
@@ -38,6 +38,7 @@ import (
        "io"
        "maps"
        "slices"
+       "sort"
        "strings"
        "text/tabwriter"
 )
@@ -163,20 +164,31 @@ func (p *pstate) sortUnits(units []extcu) {
        })
 }
 
-// EmitTextual writes the accumulated coverage data in the legacy
-// cmd/cover text format to the writer 'w'. We sort the data items by
+// EmitTextual writes the accumulated coverage data for 'pkgs' in the legacy
+// cmd/cover text format to the writer 'w'; if pkgs is empty, text output
+// is emitted for all packages recorded.  We sort the data items by
 // importpath, source file, and line number before emitting (this sorting
 // is not explicitly mandated by the format, but seems like a good idea
 // for repeatable/deterministic dumps).
-func (fm *Formatter) EmitTextual(w io.Writer) error {
+func (fm *Formatter) EmitTextual(pkgs []string, w io.Writer) error {
        if fm.cm == coverage.CtrModeInvalid {
                panic("internal error, counter mode unset")
        }
+       if len(pkgs) == 0 {
+               pkgs = make([]string, 0, len(fm.pm))
+               for importpath := range fm.pm {
+                       pkgs = append(pkgs, importpath)
+               }
+       }
        if _, err := fmt.Fprintf(w, "mode: %s\n", fm.cm.String()); err != nil {
                return err
        }
-       for _, importpath := range slices.Sorted(maps.Keys(fm.pm)) {
+       sort.Strings(pkgs)
+       for _, importpath := range pkgs {
                p := fm.pm[importpath]
+               if p == nil {
+                       continue
+               }
                units := make([]extcu, 0, len(p.unitTable))
                for u := range p.unitTable {
                        units = append(units, u)