cmd/go: merge module support from x/vgo repo

This CL corresponds to CL 123361, the final manual CL in that repo,
making this the final manual sync.

All future commits will happen in this repo (the main Go repo),
and we'll update x/vgo automatically with a fixed patch+script.

Change-Id: I572243309c1809727604fd704705a23c30e85d1a
Reviewed-on: https://go-review.googlesource.com/123576
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

1 files changed, 104 insertions, 154 deletions

diff --git a/src/cmd/go/internal/modfetch/coderepo_test.go b/src/cmd/go/internal/modfetch/coderepo_test.go
index e3b106e195..b1790e6f42 100644
--- a/src/cmd/go/internal/modfetch/coderepo_test.go
+++ b/src/cmd/go/internal/modfetch/coderepo_test.go
@@ -19,10 +19,6 @@ import (
 	"cmd/go/internal/modfetch/codehost"
 )
 
-func init() {
-	isTest = true
-}
-
 func TestMain(m *testing.M) {
 	os.Exit(testMain(m))
 }
@@ -38,6 +34,15 @@ func testMain(m *testing.M) int {
 	return m.Run()
 }
 
+const (
+	vgotest1git = "github.com/rsc/vgotest1"
+	vgotest1hg  = "vcs-test.golang.org/hg/vgotest1.hg"
+)
+
+var altVgotests = []string{
+	vgotest1hg,
+}
+
 var codeRepoTests = []struct {
 	path     string
 	lookerr  string
@@ -86,12 +91,12 @@ var codeRepoTests = []struct {
 		name:    "80d85c5d4d17598a0e9055e7c175a32b415d6128",
 		short:   "80d85c5d4d17",
 		time:    time.Date(2018, 2, 19, 23, 10, 6, 0, time.UTC),
-		ziperr:  "missing go.mod",
+		ziperr:  "missing github.com/rsc/vgotest1/go.mod and .../v2/go.mod at revision v2.0.0",
 	},
 	{
 		path:    "github.com/rsc/vgotest1",
-		rev:     "80d85",
-		version: "v0.0.0-20180219231006-80d85c5d4d17",
+		rev:     "80d85c5",
+		version: "v1.0.0",
 		name:    "80d85c5d4d17598a0e9055e7c175a32b415d6128",
 		short:   "80d85c5d4d17",
 		time:    time.Date(2018, 2, 19, 23, 10, 6, 0, time.UTC),
@@ -104,7 +109,7 @@ var codeRepoTests = []struct {
 	{
 		path:    "github.com/rsc/vgotest1",
 		rev:     "mytag",
-		version: "v0.0.0-20180219231006-80d85c5d4d17",
+		version: "v1.0.0",
 		name:    "80d85c5d4d17598a0e9055e7c175a32b415d6128",
 		short:   "80d85c5d4d17",
 		time:    time.Date(2018, 2, 19, 23, 10, 6, 0, time.UTC),
@@ -116,32 +121,32 @@ var codeRepoTests = []struct {
 	},
 	{
 		path:     "github.com/rsc/vgotest1/v2",
-		rev:      "80d85",
-		version:  "v2.0.0-20180219231006-80d85c5d4d17",
+		rev:      "80d85c5",
+		version:  "v2.0.0",
 		name:     "80d85c5d4d17598a0e9055e7c175a32b415d6128",
 		short:    "80d85c5d4d17",
 		time:     time.Date(2018, 2, 19, 23, 10, 6, 0, time.UTC),
-		gomoderr: "missing go.mod",
-		ziperr:   "missing go.mod",
+		gomoderr: "missing github.com/rsc/vgotest1/go.mod and .../v2/go.mod at revision v2.0.0",
+		ziperr:   "missing github.com/rsc/vgotest1/go.mod and .../v2/go.mod at revision v2.0.0",
 	},
 	{
 		path:    "github.com/rsc/vgotest1/v54321",
-		rev:     "80d85",
+		rev:     "80d85c5",
 		version: "v54321.0.0-20180219231006-80d85c5d4d17",
 		name:    "80d85c5d4d17598a0e9055e7c175a32b415d6128",
 		short:   "80d85c5d4d17",
 		time:    time.Date(2018, 2, 19, 23, 10, 6, 0, time.UTC),
-		ziperr:  "missing go.mod",
+		ziperr:  "missing github.com/rsc/vgotest1/go.mod and .../v54321/go.mod at revision 80d85c5d4d17",
 	},
 	{
 		path: "github.com/rsc/vgotest1/submod",
 		rev:  "v1.0.0",
-		err:  "unknown revision \"submod/v1.0.0\"",
+		err:  "unknown revision submod/v1.0.0",
 	},
 	{
 		path: "github.com/rsc/vgotest1/submod",
 		rev:  "v1.0.3",
-		err:  "unknown revision \"submod/v1.0.3\"",
+		err:  "unknown revision submod/v1.0.3",
 	},
 	{
 		path:    "github.com/rsc/vgotest1/submod",
@@ -188,7 +193,7 @@ var codeRepoTests = []struct {
 		name:     "f18795870fb14388a21ef3ebc1d75911c8694f31",
 		short:    "f18795870fb1",
 		time:     time.Date(2018, 2, 19, 23, 16, 4, 0, time.UTC),
-		gomoderr: "v2/go.mod has non-.../v2 module path",
+		gomoderr: "github.com/rsc/vgotest1/v2/go.mod has non-.../v2 module path \"github.com/rsc/vgotest\" at revision v2.0.3",
 	},
 	{
 		path:     "github.com/rsc/vgotest1/v2",
@@ -197,7 +202,7 @@ var codeRepoTests = []struct {
 		name:     "1f863feb76bc7029b78b21c5375644838962f88d",
 		short:    "1f863feb76bc",
 		time:     time.Date(2018, 2, 20, 0, 3, 38, 0, time.UTC),
-		gomoderr: "both go.mod and v2/go.mod claim .../v2 module",
+		gomoderr: "github.com/rsc/vgotest1/go.mod and .../v2/go.mod both have .../v2 module paths at revision v2.0.4",
 	},
 	{
 		path:    "github.com/rsc/vgotest1/v2",
@@ -209,33 +214,6 @@ var codeRepoTests = []struct {
 		gomod:   "module \"github.com/rsc/vgotest1/v2\" // v2/go.mod\n",
 	},
 	{
-		path:    "go.googlesource.com/scratch",
-		rev:     "0f302529858",
-		version: "v0.0.0-20180220024720-0f3025298580",
-		name:    "0f30252985809011f026b5a2d5cf456e021623da",
-		short:   "0f3025298580",
-		time:    time.Date(2018, 2, 20, 2, 47, 20, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule go.googlesource.com/scratch\n",
-	},
-	{
-		path:    "go.googlesource.com/scratch/rsc",
-		rev:     "0f302529858",
-		version: "v0.0.0-20180220024720-0f3025298580",
-		name:    "0f30252985809011f026b5a2d5cf456e021623da",
-		short:   "0f3025298580",
-		time:    time.Date(2018, 2, 20, 2, 47, 20, 0, time.UTC),
-		gomod:   "",
-	},
-	{
-		path:     "go.googlesource.com/scratch/cbro",
-		rev:      "0f302529858",
-		version:  "v0.0.0-20180220024720-0f3025298580",
-		name:     "0f30252985809011f026b5a2d5cf456e021623da",
-		short:    "0f3025298580",
-		time:     time.Date(2018, 2, 20, 2, 47, 20, 0, time.UTC),
-		gomoderr: "missing go.mod",
-	},
-	{
 		// redirect to github
 		path:    "rsc.io/quote",
 		rev:     "v1.0.0",
@@ -274,27 +252,26 @@ var codeRepoTests = []struct {
 	},
 	{
 		// package in subdirectory - custom domain
-		path:    "golang.org/x/net/context",
-		lookerr: "module root is \"golang.org/x/net\"",
+		// In general we can't reject these definitively in Lookup,
+		// but gopkg.in is special.
+		path:    "gopkg.in/yaml.v2/abc",
+		lookerr: "invalid module path \"gopkg.in/yaml.v2/abc\"",
 	},
 	{
 		// package in subdirectory - github
-		path:     "github.com/rsc/quote/buggy",
-		rev:      "c4d4236f",
-		version:  "v0.0.0-20180214154420-c4d4236f9242",
-		name:     "c4d4236f92427c64bfbcf1cc3f8142ab18f30b22",
-		short:    "c4d4236f9242",
-		time:     time.Date(2018, 2, 14, 15, 44, 20, 0, time.UTC),
-		gomoderr: "missing go.mod",
+		// Because it's a package, Stat should fail entirely.
+		path: "github.com/rsc/quote/buggy",
+		rev:  "c4d4236f",
+		err:  "missing github.com/rsc/quote/buggy/go.mod at revision c4d4236f9242",
 	},
 	{
 		path:    "gopkg.in/yaml.v2",
 		rev:     "d670f940",
-		version: "v2.0.0-20180109114331-d670f9405373",
+		version: "v2.0.0",
 		name:    "d670f9405373e636a5a2765eea47fac0c9bc91a4",
 		short:   "d670f9405373",
 		time:    time.Date(2018, 1, 9, 11, 43, 31, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule gopkg.in/yaml.v2\n",
+		gomod:   "module gopkg.in/yaml.v2\n",
 	},
 	{
 		path:    "gopkg.in/check.v1",
@@ -303,12 +280,12 @@ var codeRepoTests = []struct {
 		name:    "20d25e2804050c1cd24a7eea1e7a6447dd0e74ec",
 		short:   "20d25e280405",
 		time:    time.Date(2016, 12, 8, 18, 13, 25, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule gopkg.in/check.v1\n",
+		gomod:   "module gopkg.in/check.v1\n",
 	},
 	{
 		path:    "gopkg.in/yaml.v2",
 		rev:     "v2",
-		version: "v2.0.0-20180328195020-5420a8b6744d",
+		version: "v2.2.1",
 		name:    "5420a8b6744d3b0345ab293f6fcba19c978f1183",
 		short:   "5420a8b6744d",
 		time:    time.Date(2018, 3, 28, 19, 50, 20, 0, time.UTC),
@@ -317,11 +294,11 @@ var codeRepoTests = []struct {
 	{
 		path:    "vcs-test.golang.org/go/mod/gitrepo1",
 		rev:     "master",
-		version: "v0.0.0-20180417194322-ede458df7cd0",
+		version: "v1.2.4-annotated",
 		name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
 		short:   "ede458df7cd0",
 		time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule vcs-test.golang.org/go/mod/gitrepo1\n",
+		gomod:   "module vcs-test.golang.org/go/mod/gitrepo1\n",
 	},
 	{
 		path:    "gopkg.in/natefinch/lumberjack.v2",
@@ -330,7 +307,7 @@ var codeRepoTests = []struct {
 		name:    "a96e63847dc3c67d17befa69c303767e2f84e54f",
 		short:   "a96e63847dc3",
 		time:    time.Date(2017, 5, 31, 16, 3, 50, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule gopkg.in/natefinch/lumberjack.v2\n",
+		gomod:   "module gopkg.in/natefinch/lumberjack.v2\n",
 	},
 	{
 		path: "gopkg.in/natefinch/lumberjack.v2",
@@ -345,7 +322,7 @@ var codeRepoTests = []struct {
 		name:    "a96e63847dc3c67d17befa69c303767e2f84e54f",
 		short:   "a96e63847dc3",
 		time:    time.Date(2017, 5, 31, 16, 3, 50, 0, time.UTC),
-		gomod:   "//vgo 0.0.4\n\nmodule gopkg.in/natefinch/lumberjack.v2\n",
+		gomod:   "module gopkg.in/natefinch/lumberjack.v2\n",
 	},
 }
 
@@ -358,15 +335,15 @@ func TestCodeRepo(t *testing.T) {
 	}
 	defer os.RemoveAll(tmpdir)
 	for _, tt := range codeRepoTests {
-		t.Run(strings.Replace(tt.path, "/", "_", -1)+"/"+tt.rev, func(t *testing.T) {
+		f := func(t *testing.T) {
 			repo, err := Lookup(tt.path)
-			if err != nil {
-				if tt.lookerr != "" {
-					if err.Error() == tt.lookerr {
-						return
-					}
-					t.Errorf("Lookup(%q): %v, want error %q", tt.path, err, tt.lookerr)
+			if tt.lookerr != "" {
+				if err != nil && err.Error() == tt.lookerr {
+					return
 				}
+				t.Errorf("Lookup(%q): %v, want error %q", tt.path, err, tt.lookerr)
+			}
+			if err != nil {
 				t.Fatalf("Lookup(%q): %v", tt.path, err)
 			}
 			if tt.mpath == "" {
@@ -446,57 +423,62 @@ func TestCodeRepo(t *testing.T) {
 					t.Fatalf("zip = %v\nwant %v\n", names, tt.zip)
 				}
 			}
-		})
+		}
+		t.Run(strings.Replace(tt.path, "/", "_", -1)+"/"+tt.rev, f)
+		if strings.HasPrefix(tt.path, vgotest1git) {
+			for _, alt := range altVgotests {
+				// Note: Communicating with f through tt; should be cleaned up.
+				old := tt
+				tt.path = alt + strings.TrimPrefix(tt.path, vgotest1git)
+				if strings.HasPrefix(tt.mpath, vgotest1git) {
+					tt.mpath = alt + strings.TrimPrefix(tt.mpath, vgotest1git)
+				}
+				var m map[string]string
+				if alt == vgotest1hg {
+					m = hgmap
+				}
+				tt.version = remap(tt.version, m)
+				tt.name = remap(tt.name, m)
+				tt.short = remap(tt.short, m)
+				tt.rev = remap(tt.rev, m)
+				tt.gomoderr = remap(tt.gomoderr, m)
+				tt.ziperr = remap(tt.ziperr, m)
+				t.Run(strings.Replace(tt.path, "/", "_", -1)+"/"+tt.rev, f)
+				tt = old
+			}
+		}
 	}
 }
 
-var importTests = []struct {
-	path  string
-	mpath string
-	err   string
-}{
-	{
-		path:  "golang.org/x/net/context",
-		mpath: "golang.org/x/net",
-	},
-	{
-		path:  "github.com/rsc/quote/buggy",
-		mpath: "github.com/rsc/quote",
-	},
-	{
-		path:  "golang.org/x/net",
-		mpath: "golang.org/x/net",
-	},
-	{
-		path:  "github.com/rsc/quote",
-		mpath: "github.com/rsc/quote",
-	},
-	{
-		path: "golang.org/x/foo/bar",
-		err:  "unknown module golang.org/x/foo/bar: no go-import tags",
-	},
+var hgmap = map[string]string{
+	"github.com/rsc/vgotest1/":                 "vcs-test.golang.org/hg/vgotest1.hg/",
+	"f18795870fb14388a21ef3ebc1d75911c8694f31": "a9ad6d1d14eb544f459f446210c7eb3b009807c6",
+	"ea65f87c8f52c15ea68f3bdd9925ef17e20d91e9": "f1fc0f22021b638d073d31c752847e7bf385def7",
+	"b769f2de407a4db81af9c5de0a06016d60d2ea09": "92c7eb888b4fac17f1c6bd2e1060a1b881a3b832",
+	"8afe2b2efed96e0880ecd2a69b98a53b8c2738b6": "4e58084d459ae7e79c8c2264d0e8e9a92eb5cd44",
+	"2f615117ce481c8efef46e0cc0b4b4dccfac8fea": "879ea98f7743c8eff54f59a918f3a24123d1cf46",
+	"80d85c5d4d17598a0e9055e7c175a32b415d6128": "e125018e286a4b09061079a81e7b537070b7ff71",
+	"1f863feb76bc7029b78b21c5375644838962f88d": "bf63880162304a9337477f3858f5b7e255c75459",
 }
 
-func TestImport(t *testing.T) {
-	testenv.MustHaveExternalNetwork(t)
-
-	for _, tt := range importTests {
-		t.Run(strings.Replace(tt.path, "/", "_", -1), func(t *testing.T) {
-			repo, info, err := Import(tt.path, nil)
-			if err != nil {
-				if tt.err != "" {
-					if err.Error() == tt.err {
-						return
-					}
-					t.Errorf("Import(%q): %v, want error %q", tt.path, err, tt.err)
-				}
-				t.Fatalf("Lookup(%q): %v", tt.path, err)
-			}
-			if mpath := repo.ModulePath(); mpath != tt.mpath {
-				t.Errorf("repo.ModulePath() = %q (%v), want %q", mpath, info.Version, tt.mpath)
+func remap(name string, m map[string]string) string {
+	if m[name] != "" {
+		return m[name]
+	}
+	if codehost.AllHex(name) {
+		for k, v := range m {
+			if strings.HasPrefix(k, name) {
+				return v[:len(name)]
 			}
-		})
+		}
 	}
+	for k, v := range m {
+		name = strings.Replace(name, k, v, -1)
+		if codehost.AllHex(k) {
+			name = strings.Replace(name, k[:12], v[:12], -1)
+		}
+	}
+	return name
 }
 
 var codeRepoVersionsTests = []struct {
@@ -528,7 +510,7 @@ var codeRepoVersionsTests = []struct {
 	},
 	{
 		path:     "gopkg.in/natefinch/lumberjack.v2",
-		versions: []string{},
+		versions: nil,
 	},
 }
 
@@ -571,6 +553,10 @@ var latestTests = []struct {
 		version: "v0.0.0-20180219223237-a08abb797a67",
 	},
 	{
+		path: "github.com/rsc/vgotest1/subdir",
+		err:  "missing github.com/rsc/vgotest1/subdir/go.mod at revision a08abb797a67",
+	},
+	{
 		path:    "swtch.com/testmod",
 		version: "v1.1.1",
 	},
@@ -601,6 +587,9 @@ func TestLatest(t *testing.T) {
 				}
 				t.Fatalf("Latest(): %v", err)
 			}
+			if tt.err != "" {
+				t.Fatalf("Latest() = %v, want error %q", info.Version, tt.err)
+			}
 			if info.Version != tt.version {
 				t.Fatalf("Latest() = %v, want %v", info.Version, tt.version)
 			}
@@ -610,12 +599,10 @@ func TestLatest(t *testing.T) {
 
 // fixedTagsRepo is a fake codehost.Repo that returns a fixed list of tags
 type fixedTagsRepo struct {
-	root string
 	tags []string
 }
 
 func (ch *fixedTagsRepo) Tags(string) ([]string, error)                  { return ch.tags, nil }
-func (ch *fixedTagsRepo) Root() string                                   { return ch.root }
 func (ch *fixedTagsRepo) Latest() (*codehost.RevInfo, error)             { panic("not impl") }
 func (ch *fixedTagsRepo) ReadFile(string, string, int64) ([]byte, error) { panic("not impl") }
 func (ch *fixedTagsRepo) ReadZip(string, string, int64) (io.ReadCloser, string, error) {
@@ -626,7 +613,6 @@ func (ch *fixedTagsRepo) Stat(string) (*codehost.RevInfo, error) { panic("not im
 func TestNonCanonicalSemver(t *testing.T) {
 	root := "golang.org/x/issue24476"
 	ch := &fixedTagsRepo{
-		root: root,
 		tags: []string{
 			"", "huh?", "1.0.1",
 			// what about "version 1 dot dogcow"?
@@ -637,7 +623,7 @@ func TestNonCanonicalSemver(t *testing.T) {
 		},
 	}
 
-	cr, err := newCodeRepo(ch, root)
+	cr, err := newCodeRepo(ch, root, root)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -650,39 +636,3 @@ func TestNonCanonicalSemver(t *testing.T) {
 		t.Fatal("unexpected versions returned:", v)
 	}
 }
-
-var modPathTests = []struct {
-	input    []byte
-	expected string
-}{
-	{input: []byte("module \"github.com/rsc/vgotest\""), expected: "github.com/rsc/vgotest"},
-	{input: []byte("module github.com/rsc/vgotest"), expected: "github.com/rsc/vgotest"},
-	{input: []byte("module  \"github.com/rsc/vgotest\""), expected: "github.com/rsc/vgotest"},
-	{input: []byte("module  github.com/rsc/vgotest"), expected: "github.com/rsc/vgotest"},
-	{input: []byte("module `github.com/rsc/vgotest`"), expected: "github.com/rsc/vgotest"},
-	{input: []byte("module \"github.com/rsc/vgotest/v2\""), expected: "github.com/rsc/vgotest/v2"},
-	{input: []byte("module github.com/rsc/vgotest/v2"), expected: "github.com/rsc/vgotest/v2"},
-	{input: []byte("module \"gopkg.in/yaml.v2\""), expected: "gopkg.in/yaml.v2"},
-	{input: []byte("module gopkg.in/yaml.v2"), expected: "gopkg.in/yaml.v2"},
-	{input: []byte("module \"gopkg.in/check.v1\"\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module \"gopkg.in/check.v1\n\""), expected: ""},
-	{input: []byte("module gopkg.in/check.v1\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module \"gopkg.in/check.v1\"\r\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module gopkg.in/check.v1\r\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module \"gopkg.in/check.v1\"\n\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module gopkg.in/check.v1\n\n"), expected: "gopkg.in/check.v1"},
-	{input: []byte("module \n\"gopkg.in/check.v1\"\n\n"), expected: ""},
-	{input: []byte("module \ngopkg.in/check.v1\n\n"), expected: ""},
-	{input: []byte("module \"gopkg.in/check.v1\"asd"), expected: ""},
-}
-
-func TestModPath(t *testing.T) {
-	for _, test := range modPathTests {
-		t.Run(string(test.input), func(t *testing.T) {
-			result := modPath(test.input)
-			if result != test.expected {
-				t.Fatalf("modPath(%s): %s, want %s", string(test.input), result, test.expected)
-			}
-		})
-	}
-}