feat: url based data loading system

internal/data/format/hcl/decoder_handler.go

@@ -0,0 +1,165 @@
+package hcl
+
+import (
+	"io"
+	"net/url"
+	"path"
+	"path/filepath"
+
+	"forge.cadoles.com/wpetit/formidable/internal/data/format"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/gohcl"
+	"github.com/hashicorp/hcl/v2/hclparse"
+	"github.com/pkg/errors"
+	"github.com/zclconf/go-cty/cty"
+	"github.com/zclconf/go-cty/cty/function"
+	"github.com/zclconf/go-cty/cty/gocty"
+)
+
+const (
+	ExtensionHCL = ".hcl"
+	FormatHCL    = "hcl"
+)
+
+type DecoderHandler struct {
+	ctx *hcl.EvalContext
+}
+
+func (d *DecoderHandler) Match(url *url.URL) bool {
+	ext := filepath.Ext(path.Join(url.Host, url.Path))
+
+	return ext == ExtensionHCL ||
+		format.MatchURLQueryFormat(url, FormatHCL)
+}
+
+func (d *DecoderHandler) Decode(url *url.URL, reader io.Reader) (interface{}, error) {
+	data, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	ctx := d.ctx
+	if ctx == nil {
+		ctx = &hcl.EvalContext{
+			Variables: make(map[string]cty.Value),
+			Functions: make(map[string]function.Function),
+		}
+	}
+
+	parser := hclparse.NewParser()
+
+	file, diags := parser.ParseHCL(data, url.String())
+	if diags.HasErrors() {
+		return nil, errors.WithStack(diags)
+	}
+
+	var tree map[string]interface{}
+
+	diags = gohcl.DecodeBody(file.Body, ctx, &tree)
+	if diags.HasErrors() {
+		return nil, errors.WithStack(diags)
+	}
+
+	ctx = ctx.NewChild()
+
+	values, err := hclTreeToRawValues(ctx, tree)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return values, nil
+}
+
+func NewDecoderHandler(ctx *hcl.EvalContext) *DecoderHandler {
+	return &DecoderHandler{ctx}
+}
+
+func hclTreeToRawValues(ctx *hcl.EvalContext, tree map[string]interface{}) (map[string]interface{}, error) {
+	values := make(map[string]interface{})
+
+	for key, branch := range tree {
+		v, err := hclBranchToRawValue(ctx, branch)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		values[key] = v
+	}
+
+	return values, nil
+}
+
+func hclBranchToRawValue(ctx *hcl.EvalContext, branch interface{}) (interface{}, error) {
+	switch typ := branch.(type) {
+	case *hcl.Attribute:
+		val, diags := typ.Expr.Value(ctx)
+		if diags.HasErrors() {
+			return nil, errors.WithStack(diags)
+		}
+
+		raw, err := ctyValueToRaw(ctx, val)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		return raw, nil
+	default:
+		return nil, errors.Errorf("unexpected type '%T'", typ)
+	}
+}
+
+func ctyValueToRaw(ctx *hcl.EvalContext, val cty.Value) (interface{}, error) {
+	if val.Type().Equals(cty.Bool) {
+		var raw bool
+
+		if err := gocty.FromCtyValue(val, &raw); err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		return raw, nil
+	} else if val.Type().Equals(cty.Number) {
+		var raw float64
+
+		if err := gocty.FromCtyValue(val, &raw); err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		return raw, nil
+	} else if val.Type().Equals(cty.String) {
+		var raw string
+
+		if err := gocty.FromCtyValue(val, &raw); err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		return raw, nil
+	} else if val.Type().IsObjectType() {
+		obj := make(map[string]interface{})
+
+		for k, v := range val.AsValueMap() {
+			rv, err := ctyValueToRaw(ctx, v)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			obj[k] = rv
+		}
+
+		return obj, nil
+	} else if val.Type().IsTupleType() {
+		sl := make([]interface{}, 0)
+
+		for _, v := range val.AsValueSlice() {
+			rv, err := ctyValueToRaw(ctx, v)
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			sl = append(sl, rv)
+		}
+
+		return sl, nil
+	}
+
+	return nil, errors.Errorf("unexpected cty.Type '%s'", val.Type().FriendlyName())
+}

internal/data/format/hcl/decoder_handler_test.go

@@ -0,0 +1,78 @@
+package hcl
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/pkg/errors"
+)
+
+type parserHandlerTestCase struct {
+	Path             string
+	ExpectMatch      bool
+	ExpectParseError bool
+}
+
+var parserHandlerTestCases = []parserHandlerTestCase{
+	{
+		Path:             "testdata/dummy.hcl",
+		ExpectMatch:      true,
+		ExpectParseError: false,
+	},
+	{
+		Path:             "file://testdata/dummy_no_ext?format=hcl",
+		ExpectMatch:      true,
+		ExpectParseError: false,
+	},
+}
+
+func TestDecoderHandler(t *testing.T) {
+	t.Parallel()
+
+	handler := NewDecoderHandler(nil)
+
+	for _, tc := range parserHandlerTestCases {
+		func(tc parserHandlerTestCase) {
+			t.Run(fmt.Sprintf("Parse '%s'", tc.Path), func(t *testing.T) {
+				t.Parallel()
+
+				url, err := url.Parse(tc.Path)
+				if err != nil {
+					t.Fatal(errors.Wrapf(err, "could not parse url '%s'", tc.Path))
+				}
+
+				if e, g := tc.ExpectMatch, handler.Match(url); e != g {
+					t.Errorf("URL '%s': expected matching result '%v', got '%v'", url.String(), e, g)
+				}
+
+				if !tc.ExpectMatch {
+					return
+				}
+
+				cleanedPath := filepath.Join(url.Host, url.Path)
+
+				file, err := os.Open(cleanedPath)
+				if err != nil {
+					t.Fatal(errors.Wrapf(err, "could not open file '%s'", cleanedPath))
+				}
+
+				defer func() {
+					if err := file.Close(); err != nil {
+						t.Error(errors.Wrapf(err, "could not close file '%s'", cleanedPath))
+					}
+				}()
+
+				if _, err := handler.Decode(url, file); err != nil && !tc.ExpectParseError {
+					t.Fatal(errors.Wrapf(err, "could not parse file '%s'", tc.Path))
+				}
+
+				if tc.ExpectParseError {
+					t.Fatal(errors.Errorf("no error was returned as expected when opening url '%s'", url.String()))
+				}
+			})
+		}(tc)
+	}
+}

internal/data/format/hcl/testdata/dummy.hcl

@@ -0,0 +1,19 @@
+test = 1
+
+test1 = 2 + 1
+
+foo = {
+  description = "Ça fait des trucs"
+  type = "object"
+  properties = {
+    type = "string"
+    minLength = 5
+  }
+  test = [
+    "foo", 
+    {
+      test = "foo"
+    },
+    5 + 5.2
+  ]
+}

internal/data/format/hcl/testdata/dummy_no_ext

@@ -0,0 +1 @@
+foo = "bar"