cmd/go: add a Latest field to the output of 'go mod download -json'

Fixes #32239

Change-Id: I5723abaa9b6bed7e8fb2d95f749a4e03ecc8741b
Reviewed-on: https://go-review.googlesource.com/c/go/+/183841
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 6541e085ccff517da5cde4a1c94aebfe6613115f..44d07c119774dc59be0b0937cff9ff9fc702aa47 100644 (file)
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -1008,6 +1008,7 @@
 //         Dir      string // absolute path to cached source root directory
 //         Sum      string // checksum for path, version (as in go.sum)
 //         GoModSum string // checksum for go.mod (as in go.sum)
+//         Latest   bool   // would @latest resolve to this version?
 //     }
 //
 // See 'go help modules' for more about module queries.

diff --git a/src/cmd/go/internal/modcmd/download.go b/src/cmd/go/internal/modcmd/download.go
index 71b660d6fde326e7f468794db4a5f1c8673fff43..1137982e473069d3103debc59f5dfeab5ef0e38d 100644 (file)
--- a/src/cmd/go/internal/modcmd/download.go
+++ b/src/cmd/go/internal/modcmd/download.go
@@ -43,6 +43,7 @@ corresponding to this Go struct:
         Dir      string // absolute path to cached source root directory
         Sum      string // checksum for path, version (as in go.sum)
         GoModSum string // checksum for go.mod (as in go.sum)
+        Latest   bool   // would @latest resolve to this version?
     }
 
 See 'go help modules' for more about module queries.
@@ -65,6 +66,7 @@ type moduleJSON struct {
        Dir      string `json:",omitempty"`
        Sum      string `json:",omitempty"`
        GoModSum string `json:",omitempty"`
+       Latest   bool   `json:",omitempty"`
 }
 
 func runDownload(cmd *base.Command, args []string) {
@@ -98,6 +100,26 @@ func runDownload(cmd *base.Command, args []string) {
                work.Add(m)
        }
 
+       latest := map[string]string{} // path → version
+       if *downloadJSON {
+               // We need to populate the Latest field, but if the main module depends on a
+               // version newer than latest — or if the version requested on the command
+               // line is itself newer than latest — that's not trivial to determine from
+               // the info returned by ListModules. Instead, we issue a separate
+               // ListModules request for "latest", which should be inexpensive relative to
+               // downloading the modules.
+               var latestArgs []string
+               for _, m := range mods {
+                       latestArgs = append(latestArgs, m.Path+"@latest")
+               }
+
+               for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
+                       if info.Version != "" {
+                               latest[info.Path] = info.Version
+                       }
+               }
+       }
+
        work.Do(10, func(item interface{}) {
                m := item.(*moduleJSON)
                var err error
@@ -128,6 +150,9 @@ func runDownload(cmd *base.Command, args []string) {
                        m.Error = err.Error()
                        return
                }
+               if latest[m.Path] == m.Version {
+                       m.Latest = true
+               }
        })
 
        if *downloadJSON {

diff --git a/src/cmd/go/testdata/script/mod_download.txt b/src/cmd/go/testdata/script/mod_download.txt
index c6729c71a299db0af28439283f04bc724b9ceb6a..75e4acbab050c35668706ecead4c325715b7060b 100644 (file)
--- a/src/cmd/go/testdata/script/mod_download.txt
+++ b/src/cmd/go/testdata/script/mod_download.txt
@@ -17,6 +17,7 @@ stderr 'this.domain.is.invalid'
 stdout '"Error": ".*this.domain.is.invalid.*"'
 
 # download -json with version should print JSON
+# and download the .info file for the 'latest' version.
 go mod download -json 'rsc.io/quote@<=v1.5.0'
 stdout '^\t"Path": "rsc.io/quote"'
 stdout '^\t"Version": "v1.5.0"'
@@ -27,13 +28,14 @@ stdout '^\t"Sum": "h1:6fJa6E\+wGadANKkUMlZ0DhXFpoKlslOQDCo259XtdIE="'  # hash of
 stdout '^\t"GoModSum": "h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe\+TKr0="'
 ! stdout '"Error"'
 
+exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.2.info
+
 # download queries above should not have added to go.mod.
 go list -m all
 ! stdout rsc.io
 
 # add to go.mod so we can test non-query downloads
 go mod edit -require rsc.io/quote@v1.5.2
-! exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.2.info
 ! exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.2.mod
 ! exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.2.zip
 

diff --git a/src/cmd/go/testdata/script/mod_download_latest.txt b/src/cmd/go/testdata/script/mod_download_latest.txt
new file mode 100644 (file)
index 0000000..60d860e
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_download_latest.txt
@@ -0,0 +1,20 @@
+env GO111MODULE=on
+
+# If the module is the latest version of itself,
+# the Latest field should be set.
+go mod download -json rsc.io/quote@v1.5.2
+stdout '"Latest":\s*true'
+
+# If the module is older than latest, the field should be unset.
+go mod download -json rsc.io/quote@v1.5.1
+! stdout '"Latest":'
+
+# If the module is newer than "latest", the field should be unset...
+go mod download -json rsc.io/quote@v1.5.3-pre1
+! stdout '"Latest":'
+
+# ...even if that version is also what is required by the main module.
+go mod init example.com
+go mod edit -require rsc.io/quote@v1.5.3-pre1
+go mod download -json rsc.io/quote@v1.5.3-pre1
+! stdout '"Latest":'

diff --git a/src/cmd/go/testdata/script/mod_list_upgrade.txt b/src/cmd/go/testdata/script/mod_list_upgrade.txt
index 474df0dc269e4401bc99875f019fa01c0c080985..f2d06490920151e090821eae5ca8e267ba834ccb 100644 (file)
--- a/src/cmd/go/testdata/script/mod_list_upgrade.txt
+++ b/src/cmd/go/testdata/script/mod_list_upgrade.txt
@@ -1,8 +1,28 @@
 env GO111MODULE=on
 
+# If the current version is not latest, 'go list -u' should include its upgrade.
 go list -m -u all
 stdout 'rsc.io/quote v1.2.0 \[v1\.5\.2\]'
 
+# If the current version is latest, 'go list -u' should omit the upgrade.
+go get -d rsc.io/quote@v1.5.2
+go list -m -u all
+stdout 'rsc.io/quote v1.5.2$'
+
+# If the current version is newer than latest, 'go list -u' should
+# omit the upgrade.
+go get -d rsc.io/quote@v1.5.3-pre1
+go list -m -u all
+stdout 'rsc.io/quote v1.5.3-pre1$'
+
+# If the current build list has a higher version and the user asks about
+# a lower one, -u should report the upgrade for the lower one
+# but leave the build list unchanged.
+go list -m -u rsc.io/quote@v1.5.1
+stdout 'rsc.io/quote v1.5.1 \[v1.5.2\]$'
+go list -m -u rsc.io/quote
+stdout 'rsc.io/quote v1.5.3-pre1$'
+
 -- go.mod --
 module x
 require rsc.io/quote v1.2.0