Add start_with that rule

internal/arch/file/that/start_with.go

@@ -0,0 +1,44 @@
+package that
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/omissis/goarkitect/internal/arch/file"
+	"github.com/omissis/goarkitect/internal/arch/rule"
+)
+
+func StartWith(s string) *StartWithExpression {
+	return &StartWithExpression{
+		prefix: s,
+	}
+}
+
+type StartWithExpression struct {
+	prefix string
+
+	errors []error
+}
+
+func (e *StartWithExpression) GetErrors() []error {
+	return e.errors
+}
+
+func (e *StartWithExpression) Evaluate(rb rule.Builder) {
+	frb, ok := rb.(*file.RuleBuilder)
+	if !ok {
+		e.errors = append(e.errors, file.ErrInvalidRuleBuilder)
+
+		return
+	}
+
+	files := make([]string, 0)
+
+	for _, f := range frb.GetFiles() {
+		if strings.HasPrefix(filepath.Base(f), e.prefix) {
+			files = append(files, f)
+		}
+	}
+
+	frb.SetFiles(files)
+}

internal/arch/file/that/start_with_test.go

@@ -0,0 +1,64 @@
+package that_test
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+
+	"github.com/omissis/goarkitect/internal/arch/file"
+	"github.com/omissis/goarkitect/internal/arch/file/that"
+	"github.com/omissis/goarkitect/internal/arch/rule"
+)
+
+func Test_StartWith(t *testing.T) {
+	t.Parallel()
+
+	rb := func() *file.RuleBuilder {
+		rb := file.All()
+		rb.SetFiles([]string{"Dockerfile", "Makefile", "foo/bar.go"})
+
+		return rb
+	}
+
+	testCases := []struct {
+		desc        string
+		ruleBuilder *file.RuleBuilder
+		prefix      string
+		want        []string
+	}{
+		{
+			desc:        "files starting with 'foo'",
+			ruleBuilder: rb(),
+			prefix:      "foo",
+			want:        nil,
+		},
+		{
+			desc:        "files starting with 'Make'",
+			ruleBuilder: rb(),
+			prefix:      "Make",
+			want:        []string{"Makefile"},
+		},
+		{
+			desc:        "files in a subdirectory starting with 'bar",
+			ruleBuilder: rb(),
+			prefix:      "bar",
+			want:        []string{"foo/bar.go"},
+		},
+	}
+	for _, tC := range testCases {
+		tC := tC
+
+		t.Run(tC.desc, func(t *testing.T) {
+			t.Parallel()
+
+			ew := that.StartWith(tC.prefix)
+			ew.Evaluate(tC.ruleBuilder)
+
+			got := tC.ruleBuilder.GetFiles()
+			if !cmp.Equal(got, tC.want, cmp.AllowUnexported(rule.Violation{}), cmpopts.EquateEmpty()) {
+				t.Errorf("want = %+v, got = %+v", tC.want, got)
+			}
+		})
+	}
+}