refactory to move trim/apply default into schema.go (#33754)

* refactory to move trim/apply default into schema.go

* fix comments

* move schema test outside of load folder

pkg/schema/schema_test.go

@@ -1,4 +1,108 @@
 package schema
 
-// TODO tests for this stuff! Everything in this package is totally generic,
-// nothing is specific to Grafana
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"cuelang.org/go/cue"
+	"github.com/google/go-cmp/cmp"
+	"golang.org/x/tools/txtar"
+)
+
+var CasesDir = filepath.Join("testdata", "trimapplydefaults")
+
+type Case struct {
+	Name    string
+	CUE     string
+	Full    string
+	Trimmed string
+}
+
+func TestGenerate(t *testing.T) {
+	cases, err := loadCases(CasesDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, c := range cases {
+		t.Run(c.Name+" apply default value", func(t *testing.T) {
+			var r cue.Runtime
+			scmInstance, err := r.Compile(c.Name+".cue", c.CUE)
+			if err != nil {
+				t.Fatal(err)
+			}
+			inputResource := Resource{Value: c.Trimmed}
+			out, err := ApplyDefaults(inputResource, scmInstance.Value())
+			if err != nil {
+				t.Fatal(err)
+			}
+			b := []byte(out.Value.(string))
+
+			if s := cmp.Diff(string(b), c.Full); s != "" {
+				t.Fatal(s)
+			}
+		})
+	}
+
+	for _, c := range cases {
+		t.Run(c.Name+" trim default value", func(t *testing.T) {
+			var r cue.Runtime
+			scmInstance, err := r.Compile(c.Name+".cue", c.CUE)
+			if err != nil {
+				t.Fatal(err)
+			}
+			inputResource := Resource{Value: c.Full}
+			out, err := TrimDefaults(inputResource, scmInstance.Value())
+			if err != nil {
+				t.Fatal(err)
+			}
+			b := []byte(out.Value.(string))
+			if s := cmp.Diff(string(b), c.Trimmed); s != "" {
+				t.Fatal(s)
+			}
+		})
+	}
+}
+
+func loadCases(dir string) ([]Case, error) {
+	files, err := ioutil.ReadDir(dir)
+	if err != nil {
+		return nil, err
+	}
+	var cases []Case
+	for _, fi := range files {
+		file := filepath.Join(dir, fi.Name())
+		a, err := txtar.ParseFile(file)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(a.Files) != 3 {
+			return nil, fmt.Errorf("Malformed test case '%s': Must contain exactly three files (CUE, Full and Trimed), but has %d", file, len(a.Files))
+		}
+
+		fullBuffer := new(bytes.Buffer)
+		fullJson := a.Files[1].Data
+		if err := json.Compact(fullBuffer, fullJson); err != nil {
+			return nil, err
+		}
+
+		trimBuffer := new(bytes.Buffer)
+		trimedJson := a.Files[2].Data
+		if err := json.Compact(trimBuffer, trimedJson); err != nil {
+			return nil, err
+		}
+
+		cases = append(cases, Case{
+			Name:    fi.Name(),
+			CUE:     string(a.Files[0].Data),
+			Full:    fullBuffer.String(),
+			Trimmed: trimBuffer.String(),
+		})
+	}
+	return cases, nil
+}