fix: allow LICENSE rendering via gnoweb (#2417)

We allow LICENSE files to be included when adding packages, so we should
also allow them to be viewed via gnoweb.

<!-- please provide a detailed description of the changes made in this
pull request. -->

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
- [x] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

gno.land/pkg/gnoweb/gnoweb.go

@@ -111,7 +111,7 @@ func MakeApp(logger *slog.Logger, cfg Config) gotuna.App {
 	}
 	// realm routes
 	// NOTE: see rePathPart.
-	app.Router.Handle("/r/{rlmname:[a-z][a-z0-9_]*(?:/[a-z][a-z0-9_]*)+}/{filename:(?:.*\\.(?:gno|md|txt|mod)$)?}", handlerRealmFile(logger, app, &cfg))
+	app.Router.Handle("/r/{rlmname:[a-z][a-z0-9_]*(?:/[a-z][a-z0-9_]*)+}/{filename:(?:(?:.*\\.(?:gno|md|txt|mod)$)|(?:LICENSE$))?}", handlerRealmFile(logger, app, &cfg))
 	app.Router.Handle("/r/{rlmname:[a-z][a-z0-9_]*(?:/[a-z][a-z0-9_]*)+}", handlerRealmMain(logger, app, &cfg))
 	app.Router.Handle("/r/{rlmname:[a-z][a-z0-9_]*(?:/[a-z][a-z0-9_]*)+}:{querystr:.*}", handlerRealmRender(logger, app, &cfg))
 	app.Router.Handle("/p/{filepath:.*}", handlerPackageFile(logger, app, &cfg))

gno.land/pkg/gnoweb/gnoweb_test.go

@@ -46,6 +46,7 @@ func TestRoutes(t *testing.T) {
 		{"/%ED%85%8C%EC%8A%A4%ED%8A%B8", notFound, "/테스트"},
 		{"/グノー", notFound, "/グノー"},
 		{"/⚛️", notFound, "/⚛️"},
+		{"/p/demo/flow/LICENSE", ok, "BSD 3-Clause"},
 	}
 
 	config, _ := integration.TestingNodeConfig(t, gnoenv.RootDir())
@@ -67,7 +68,6 @@ func TestRoutes(t *testing.T) {
 			response := httptest.NewRecorder()
 			app.Router.ServeHTTP(response, request)
 			assert.Equal(t, r.status, response.Code)
-
 			assert.Contains(t, response.Body.String(), r.substring)
 		})
 	}

tm2/pkg/std/memfile.go

@@ -90,18 +90,23 @@ func (mempkg *MemPackage) Validate() error {
 	return nil
 }
 
+const licenseName = "LICENSE"
+
 // Splits a path into the dirpath and filename.
 func SplitFilepath(filepath string) (dirpath string, filename string) {
 	parts := strings.Split(filepath, "/")
 	if len(parts) == 1 {
 		return parts[0], ""
 	}
-	last := parts[len(parts)-1]
-	if strings.Contains(last, ".") {
+
+	switch last := parts[len(parts)-1]; {
+	case strings.Contains(last, "."):
 		return strings.Join(parts[:len(parts)-1], "/"), last
-	} else if last == "" {
+	case last == "":
 		return strings.Join(parts[:len(parts)-1], "/"), ""
-	} else {
-		return strings.Join(parts, "/"), ""
+	case last == licenseName:
+		return strings.Join(parts[:len(parts)-1], "/"), licenseName
 	}
+
+	return strings.Join(parts, "/"), ""
 }

tm2/pkg/std/memfile_test.go

@@ -270,3 +270,54 @@ func TestMemPackage_Validate(t *testing.T) {
 		})
 	}
 }
+
+func TestSplitFilepath(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name        string
+		filepath    string
+		expDirPath  string
+		expFilename string
+	}{
+		{
+			name: "empty",
+		},
+		{
+			name:       "one part",
+			filepath:   "root",
+			expDirPath: "root",
+		},
+		{
+			name:        "file",
+			filepath:    "gno.land/r/demo/avl/avl.gno",
+			expDirPath:  "gno.land/r/demo/avl",
+			expFilename: "avl.gno",
+		},
+		{
+			name:       "trailing slash",
+			filepath:   "gno.land/r/demo/avl/",
+			expDirPath: "gno.land/r/demo/avl",
+		},
+		{
+			name:        "license",
+			filepath:    "gno.land/r/demo/avl/LICENSE",
+			expDirPath:  "gno.land/r/demo/avl",
+			expFilename: "LICENSE",
+		},
+		{
+			name:       "regular path",
+			filepath:   "gno.land/p/demo/avl",
+			expDirPath: "gno.land/p/demo/avl",
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			dirPath, filename := SplitFilepath(tt.filepath)
+			assert.Equal(t, tt.expDirPath, dirPath)
+			assert.Equal(t, tt.expFilename, filename)
+		})
+	}
+}