Add functions to infer build tool (#1210)

pkg/piperutils/projectStructure.go

@@ -0,0 +1,36 @@
+package piperutils
+
+import "path/filepath"
+
+// ProjectStructure describes a directory containing source code
+type ProjectStructure struct {
+	directory string
+}
+
+// UsesMta returns `true` if the project structure directory contains typical files for mta projects (mta.yaml, mta.yml), `false` otherwise
+func (projectStructure *ProjectStructure) UsesMta() bool {
+	return projectStructure.anyFileExists("mta.yaml", "mta.yml")
+}
+
+// UsesMaven returns `true` if the project structure directory contains a pom.xml file, false otherwise
+func (projectStructure *ProjectStructure) UsesMaven() bool {
+	return projectStructure.anyFileExists("pom.xml")
+}
+
+// UsesNpm returns `true` if the project structure directory contains a package.json file, false otherwise
+func (projectStructure *ProjectStructure) UsesNpm() bool {
+	return projectStructure.anyFileExists("package.json")
+}
+
+func (projectStructure *ProjectStructure) anyFileExists(candidates ...string) bool {
+	for i := 0; i < len(candidates); i++ {
+		exists, err := FileExists(filepath.Join(projectStructure.directory, candidates[i]))
+		if err != nil {
+			continue
+		}
+		if exists {
+			return true
+		}
+	}
+	return false
+}

pkg/piperutils/projectStructure_test.go

@@ -0,0 +1,47 @@
+package piperutils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestProjectWithOnlyMtaFile(t *testing.T) {
+	projectStructure := ProjectStructure{directory: "testdata/mta"}
+	resultMta := projectStructure.UsesMta()
+	assert.True(t, resultMta)
+	resultPom := projectStructure.UsesMaven()
+	assert.False(t, resultPom)
+	resultNpm := projectStructure.UsesNpm()
+	assert.False(t, resultNpm)
+}
+
+func TestProjectWithOnlyPomFile(t *testing.T) {
+	projectStructure := ProjectStructure{directory: "testdata/maven"}
+	resultMta := projectStructure.UsesMta()
+	assert.False(t, resultMta)
+	resultPom := projectStructure.UsesMaven()
+	assert.True(t, resultPom)
+	resultNpm := projectStructure.UsesNpm()
+	assert.False(t, resultNpm)
+}
+
+func TestProjectWithOnlyNpmFile(t *testing.T) {
+	projectStructure := ProjectStructure{directory: "testdata/npm"}
+	resultMta := projectStructure.UsesMta()
+	assert.False(t, resultMta)
+	resultPom := projectStructure.UsesMaven()
+	assert.False(t, resultPom)
+	resultNpm := projectStructure.UsesNpm()
+	assert.True(t, resultNpm)
+}
+
+func TestDirectryParameterIsEmptyAndNoProjectFilesAreInIt(t *testing.T) {
+	projectStructure := ProjectStructure{}
+	resultMta := projectStructure.UsesMta()
+	assert.False(t, resultMta)
+	resultPom := projectStructure.UsesMaven()
+	assert.False(t, resultPom)
+	resultNpm := projectStructure.UsesNpm()
+	assert.False(t, resultNpm)
+}