feat(test): adding tests for the "File" struct

feat(test): moving util funcs into utils module

pkg/utils/templates.go

@@ -0,0 +1,89 @@
+package utils
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"os"
+	"text/template"
+
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+	"github.com/zclconf/go-cty/cty"
+	ctyjson "github.com/zclconf/go-cty/cty/json"
+)
+
+// The actual template processing for Go templates
+func ProcessGoTemplate(file string, configValues []byte) (string, error) {
+
+	// The JSON configuration
+	var confData map[string]interface{}
+	var res bytes.Buffer
+
+	err := json.Unmarshal(configValues, &confData)
+	CheckErr(err)
+
+	// Read the template
+	templateData, err := os.ReadFile(file)
+	CheckErr(err)
+
+	tpl, err := template.New("conf").Parse(string(templateData))
+	CheckErr(err)
+
+	CheckErr(tpl.Execute(&res, confData))
+
+	return res.String(), nil
+}
+
+// The actual template processing for HCL templates
+func ProcessHCLTemplate(file string, config []byte) (string, error) {
+
+	fct, err := os.ReadFile(file)
+	CheckErr(err)
+
+	expr, diags := hclsyntax.ParseTemplate(fct, file, hcl.Pos{Line: 0, Column: 1})
+	CheckDiags(diags)
+
+	// Retrieve values from JSON
+	var varsVal cty.Value
+	ctyType, err := ctyjson.ImpliedType(config)
+	if err != nil {
+		return "", err
+		/* Maybe one day
+		cexpr, diags := hclsyntax.ParseExpression(config, "", hcl.Pos{Line: 0, Column: 1})
+		if diags.HasErrors() {
+			panic(diags.Error())
+		}
+		varsVal, diags = cexpr.Value(&hcl.EvalContext{})
+		fmt.Println(cexpr.Variables())
+		checkDiags(diags)
+		*/
+	} else {
+		varsVal, err = ctyjson.Unmarshal(config, ctyType)
+		CheckErr(err)
+	}
+
+	ctx := &hcl.EvalContext{
+		Variables: varsVal.AsValueMap(),
+	}
+
+	for n := range ctx.Variables {
+		if !hclsyntax.ValidIdentifier(n) {
+			return "", fmt.Errorf("invalid template variable name %q: must start with a letter, followed by zero or more letters, digits, and underscores", n)
+		}
+	}
+
+	for _, traversal := range expr.Variables() {
+		root := traversal.RootName()
+		if _, ok := ctx.Variables[root]; !ok {
+			return "", fmt.Errorf("vars map does not contain key %q, referenced at %s", root, traversal[0].SourceRange())
+		}
+	}
+
+	val, diags := expr.Value(ctx)
+	if diags.HasErrors() {
+		return "", diags
+	}
+
+	return val.AsString(), nil
+}

pkg/utils/templates_test.go

@@ -0,0 +1,34 @@
+package utils
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func TestProcessHCLTemplate(t *testing.T) {
+	// load the Full configuration from a file
+	values, err := ioutil.ReadFile("../../data/config/go-test-conf.json")
+	if err != nil {
+		t.Error(err)
+	}
+
+	data, err := ProcessHCLTemplate("../../data/templates/go-test-hcl.pktpl.hcl", values)
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+	t.Logf("%s", data)
+}
+
+func TestProcessGoTemplate(t *testing.T) {
+	// load values from testing json file
+	values, err := ioutil.ReadFile("../../data/config/go-test-conf.json")
+	if err != nil {
+		t.Error(err)
+	}
+
+	data, err := ProcessGoTemplate("../../data/templates/go-test-go.tpl", values)
+	if err != nil {
+		t.Error(err)
+	}
+	t.Logf("%s", data)
+}