Add check for missing readme in library

Author: per1234

check/checkconfigurations/checkconfigurations.go

@@ -956,6 +956,21 @@ var configurations = []Type{
 		ErrorModes:      []checkmode.Type{checkmode.Default},
 		CheckFunction:   checkfunctions.ProhibitedCharactersInLibraryFolderName,
 	},
+	{
+		ProjectType:     projecttype.Library,
+		Category:        "structure",
+		Subcategory:     "",
+		ID:              "",
+		Brief:           "no readme",
+		Description:     "",
+		MessageTemplate: "No readme found. Please document your library. See: https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/about-readmes",
+		DisableModes:    nil,
+		EnableModes:     []checkmode.Type{checkmode.Default},
+		InfoModes:       nil,
+		WarningModes:    []checkmode.Type{checkmode.Default},
+		ErrorModes:      []checkmode.Type{checkmode.Strict},
+		CheckFunction:   checkfunctions.MissingReadme,
+	},
 	{
 		ProjectType:     projecttype.Sketch,
 		Category:        "structure",

check/checkfunctions/checkfunctions.go

@@ -20,6 +20,7 @@ import (
 	"regexp"
 	"strings"
 
+	"github.com/arduino/arduino-check/check/checkdata"
 	"github.com/arduino/arduino-check/check/checkresult"
 	"github.com/arduino/go-paths-helper"
 )
@@ -64,3 +65,35 @@ func containsIncorrectPathBaseCase(pathList paths.PathList, correctBaseName stri
 
 	return nil, false
 }
+
+// MissingReadme checks if the project has a readme that will be recognized by GitHub.
+func MissingReadme() (result checkresult.Type, output string) {
+	// https://github.com/github/markup/blob/master/README.md
+	readmeRegexp := regexp.MustCompile(`(?i)^readme\.(markdown)|(mdown)|(mkdn)|(md)|(textile)|(rdoc)|(org)|(creole)|(mediawiki)|(wiki)|(rst)|(asciidoc)|(adoc)|(asc)|(pod)|(txt)`)
+
+	// https://docs.github.com/en/free-pro-team@latest/github/creating-cloning-and-archiving-repositories/about-readmes#about-readmes
+	if pathContainsReadme(checkdata.ProjectPath(), readmeRegexp) ||
+		(checkdata.ProjectPath().Join("docs").Exist() && pathContainsReadme(checkdata.ProjectPath().Join("docs"), readmeRegexp)) ||
+		(checkdata.ProjectPath().Join(".github").Exist() && pathContainsReadme(checkdata.ProjectPath().Join(".github"), readmeRegexp)) {
+		return checkresult.Pass, ""
+	}
+
+	return checkresult.Fail, ""
+}
+
+// pathContainsReadme checks if the provided path contains a readme file recognized by GitHub.
+func pathContainsReadme(path *paths.Path, readmeRegexp *regexp.Regexp) bool {
+	listing, err := path.ReadDir()
+	if err != nil {
+		panic(err)
+	}
+	listing.FilterOutDirs()
+
+	for _, file := range listing {
+		if readmeRegexp.MatchString(file.Base()) {
+			return true
+		}
+	}
+
+	return false
+}

check/checkfunctions/library_test.go

@@ -381,3 +381,12 @@ func TestRecursiveLibraryWithUtilityFolder(t *testing.T) {
 
 	checkLibraryCheckFunction(RecursiveLibraryWithUtilityFolder, testTables, t)
 }
+
+func TestMissingReadme(t *testing.T) {
+	testTables := []libraryCheckFunctionTestTable{
+		{"Readme", "Readme", checkresult.Pass, ""},
+		{"No readme", "NoReadme", checkresult.Fail, ""},
+	}
+
+	checkLibraryCheckFunction(MissingReadme, testTables, t)
+}

check/checkfunctions/testdata/libraries/NoReadme/library.properties

@@ -0,0 +1,9 @@
+name=NoReadme
+version=1.0.0
+author=Cristian Maglie <c.maglie@example.com>, Pippo Pluto <pippo@example.com>
+maintainer=Cristian Maglie <c.maglie@example.com>
+sentence=A library that makes coding a web server a breeze.
+paragraph=Supports HTTP1.1 and you can do GET and POST.
+category=Communication
+url=http://example.com/
+architectures=avr

check/checkfunctions/testdata/libraries/NoReadme/src/NoReadme.h

@@ -0,0 +1,9 @@
+name=Readme
+version=1.0.0
+author=Cristian Maglie <c.maglie@example.com>, Pippo Pluto <pippo@example.com>
+maintainer=Cristian Maglie <c.maglie@example.com>
+sentence=A library that makes coding a web server a breeze.
+paragraph=Supports HTTP1.1 and you can do GET and POST.
+category=Communication
+url=http://example.com/
+architectures=avr