import: go: Add an option to use pinned versions.

The ability to pin versions is handy when having to deal to packages that
bootstrap themselves through a chain of former versions.  Not using pinned
versions in these case could introduce dependency cycles.

* guix/build-system/go.scm (guix)
(%go-version-rx): Rename to...
(%go-pseudo-version-rx): ... this.  Simplify the regular expression, which in
turns makes it more robust.
* guix/build-system/go.scm (go-version->git-ref): Adjust following the above
rename.
(go-pseudo-version?): New predicate.
(go-module-latest-version): Rename to ...
(go-module-version-string): ... this.  Rename goproxy-url argument to just
goproxy.  Add a VERSION keyword argument, update docstring and adjust to have
it used.
(go-module-available-versions): New procedure.
(%go.mod-require-directive-rx): Document regexp.
(parse-go.mod): Harmonize the way dependencies are recorded to a list of lists
rather than a list of pairs, as done for other importers.  Rewrite to directly pass
multiple values rather than a record object.  Filter the replaced modules in a
functional style.
(go-module->guix-package): Add docstring.
[version, pin-versions?]: New arguments.  Rename the GOPROXY-URL argument to
GOPROXY.  Adjust to the new returned value of fetch-go.mod, which is a string.
Fail when the provided version doesn't exist.  Return a list dependencies and
their versions when in pinned versions mode, else just the dependencies.
(go-module-recursive-import)[version, pin-versions?]: New arguments.
Honor the new arguments and guard against network errors.
* guix/scripts/import/go.scm (%default-options): Register a default value for
the goproxy argument.
(show-help): Document that a version can be specified.  Remove the --version
argument and add a --pin-versions argument.
(%options)[version]: Remove option.
[pin-versions]: Add option.
(guix-import-go): Adjust so the version provided from the module name is
honored, along the new pin-versions? argument.
* tests/go.scm: Adjust and add new tests.

1 files changed, 36 insertions, 28 deletions

diff --git a/tests/go.scm b/tests/go.scm
index fa8fa7a2a6..e5780e68b0 100644
--- a/tests/go.scm
+++ b/tests/go.scm
@@ -19,7 +19,7 @@
 ;;; Summary
 ;; Tests for guix/import/go.scm
 
-(define-module (test-import-go)
+(define-module (tests-import-go)
   #:use-module (guix base32)
   #:use-module (guix build-system go)
   #:use-module (guix import go)
@@ -147,7 +147,8 @@ require github.com/kr/pretty v0.2.1
       ("https://pkg.go.dev/github.com/go-check/check"
        . ,pkg.go.dev)
       ("https://pkg.go.dev/github.com/go-check/check?tab=licenses"
-       . ,pkg.go.dev-licence))))
+       . ,pkg.go.dev-licence)
+      ("https://proxy.golang.org/github.com/go-check/check/@v/list" . ""))))
 
 (test-begin "go")
 
@@ -169,6 +170,12 @@ require github.com/kr/pretty v0.2.1
   "daa7c04131f5"
   (go-version->git-ref "v1.2.4-0.20191109021931-daa7c04131f5"))
 
+(test-assert "go-pseudo-version? multi-digit version number"
+  (go-pseudo-version? "v1.23.1-0.20200526195155-81db48ad09cc"))
+
+(test-assert "go-pseudo-version? semantic version with rc"
+  (go-pseudo-version? "v1.4.0-rc.4.0.20200313231945-b860323f09d0"))
+
 ;;; Unit tests for (guix import go)
 
 (test-equal "go-path-escape"
@@ -185,37 +192,38 @@ require github.com/kr/pretty v0.2.1
     (sort ((@@ (guix import go) parse-go.mod) input) inf?)))
 
 (testing-parse-mod "parse-go.mod-simple"
-                   '(("good/thing" . "v1.4.5")
-                     ("new/thing/v2" . "v2.3.4")
-                     ("other/thing" . "v1.0.2"))
+                   '(("good/thing" "v1.4.5")
+                     ("new/thing/v2" "v2.3.4")
+                     ("other/thing" "v1.0.2"))
                    fixture-go-mod-simple)
 
 (testing-parse-mod "parse-go.mod-with-block"
-                   '(("A" . "v1")
-                     ("B" . "v1.0.0")
-                     ("C" . "v1.0.0")
-                     ("D" . "v1.2.3")
-                     ("E" . "dev"))
+                   '(("A" "v1")
+                     ("B" "v1.0.0")
+                     ("C" "v1.0.0")
+                     ("D" "v1.2.3")
+                     ("E" "dev"))
                    fixture-go-mod-with-block)
 
-(testing-parse-mod "parse-go.mod-complete"
-                   '(("github.com/corp/arbitrary-repo" . "v0.0.2")
-                     ("quoted.example.com/abitrary/repo" . "v0.0.2")
-                     ("one.example.com/abitrary/repo" . "v1.1.111")
-                     ("hub.jazz.net/git/user/project/sub/directory" . "v1.1.19")
-                     ("hub.jazz.net/git/user/project" . "v1.1.18")
-                     ("launchpad.net/~user/project/branch/sub/directory" . "v1.1.17")
-                     ("launchpad.net/~user/project/branch" . "v1.1.16")
-                     ("launchpad.net/project/series/sub/directory" . "v1.1.15")
-                     ("launchpad.net/project/series" . "v1.1.14")
-                     ("launchpad.net/project" . "v1.1.13")
-                     ("bitbucket.org/user/project/sub/directory" . "v1.11.21")
-                     ("bitbucket.org/user/project" . "v1.11.20")
-                     ("k8s.io/kubernetes/subproject" . "v1.1.101")
-                     ("github.com/user/project/sub/directory" . "v1.1.12")
-                     ("github.com/user/project" . "v1.1.11")
-                     ("github.com/go-check/check" . "v0.0.0-20140225173054-eb6ee6f84d0a"))
-                   fixture-go-mod-complete)
+(testing-parse-mod
+ "parse-go.mod-complete"
+ '(("github.com/corp/arbitrary-repo" "v0.0.2")
+   ("quoted.example.com/abitrary/repo" "v0.0.2")
+   ("one.example.com/abitrary/repo" "v1.1.111")
+   ("hub.jazz.net/git/user/project/sub/directory" "v1.1.19")
+   ("hub.jazz.net/git/user/project" "v1.1.18")
+   ("launchpad.net/~user/project/branch/sub/directory" "v1.1.17")
+   ("launchpad.net/~user/project/branch" "v1.1.16")
+   ("launchpad.net/project/series/sub/directory" "v1.1.15")
+   ("launchpad.net/project/series" "v1.1.14")
+   ("launchpad.net/project" "v1.1.13")
+   ("bitbucket.org/user/project/sub/directory" "v1.11.21")
+   ("bitbucket.org/user/project" "v1.11.20")
+   ("k8s.io/kubernetes/subproject" "v1.1.101")
+   ("github.com/user/project/sub/directory" "v1.1.12")
+   ("github.com/user/project" "v1.1.11")
+   ("github.com/go-check/check" "v0.0.0-20140225173054-eb6ee6f84d0a"))
+ fixture-go-mod-complete)
 
 ;;; End-to-end tests for (guix import go)
 (define (mock-http-fetch testcase)