address feedback in PR

api.go

@@ -89,7 +89,7 @@ func (api *API) validate(f apiMethod) error {
 	if _, ok := validAPIMethods[state][f]; ok {
 		return nil
 	}
-	return ApiMethodNotAllowedError{errors.Errorf("api method %s not allowed in state %s", f, state)}
+	return NewApiMethodNotAllowedError(errors.Errorf("api method %s not allowed in state %s", f, state))
 }
 
 // Query parses a PQL query out of the request and executes it.
@@ -205,7 +205,7 @@ func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 
 	index := api.Holder.Index(indexName)
 	if index == nil {
-		return nil, NotFoundError{ErrIndexNotFound}
+		return nil, NewNotFoundError(ErrIndexNotFound)
 	}
 	return index, nil
 }
@@ -253,7 +253,7 @@ func (api *API) CreateField(ctx context.Context, indexName string, fieldName str
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
-		return nil, NotFoundError{ErrIndexNotFound}
+		return nil, NewNotFoundError(ErrIndexNotFound)
 	}
 
 	// Create field.
@@ -288,7 +288,7 @@ func (api *API) DeleteField(ctx context.Context, indexName string, fieldName str
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
-		return NotFoundError{ErrIndexNotFound}
+		return NewNotFoundError(ErrIndexNotFound)
 	}
 
 	// Delete field from the index.
@@ -416,11 +416,11 @@ func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte,
 
 	reqBytes, err := ioutil.ReadAll(body)
 	if err != nil {
-		return nil, BadRequestError{errors.Wrap(err, "read body error")}
+		return nil, NewBadRequestError(errors.Wrap(err, "read body error"))
 	}
 	var req internal.BlockDataRequest
 	if err := proto.Unmarshal(reqBytes, &req); err != nil {
-		return nil, BadRequestError{errors.Wrap(err, "unmarshal body error")}
+		return nil, NewBadRequestError(errors.Wrap(err, "unmarshal body error"))
 	}
 
 	// Retrieve fragment from holder.
@@ -575,7 +575,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 	// Retrieve index from holder.
 	index := api.Holder.Index(indexName)
 	if index == nil {
-		return nil, NotFoundError{ErrIndexNotFound}
+		return nil, NewNotFoundError(ErrIndexNotFound)
 	}
 
 	// Retrieve local blocks.
@@ -717,7 +717,7 @@ func (api *API) indexField(indexName string, fieldName string, shard uint64) (*I
 	index := api.Holder.Index(indexName)
 	if index == nil {
 		api.server.logger.Printf("fragment error: index=%s, field=%s, shard=%d, err=%s", indexName, fieldName, shard, ErrIndexNotFound.Error())
-		return nil, nil, NotFoundError{ErrIndexNotFound}
+		return nil, nil, NewNotFoundError(ErrIndexNotFound)
 	}
 
 	// Retrieve field.

http/error.go

@@ -14,8 +14,6 @@
 
 package http
 
-import "bytes"
-
 // Error defines a standard application error.
 type Error struct {
 	// Machine-readable error code.
@@ -27,7 +25,5 @@ type Error struct {
 
 // Error returns the string representation of the error message.
 func (e *Error) Error() string {
-	var buf bytes.Buffer
-	buf.WriteString(e.Message)
-	return buf.String()
+	return e.Message
 }

http/handler.go

@@ -578,19 +578,14 @@ func (h *Handler) handlePostIndex(w http.ResponseWriter, r *http.Request) {
 
 	resp := successResponse{}
 
-	err := func() error {
-		// Decode request.
-		var req postIndexRequest
-		err := json.NewDecoder(r.Body).Decode(&req)
-		if err == io.EOF {
-			// If no data was provided (EOF), we still create the index
-			// with default values.
-		} else if err != nil {
-			return err
-		}
-		_, err = h.API.CreateIndex(r.Context(), indexName, req.Options)
-		return err
-	}()
+	// Decode request.
+	var req postIndexRequest
+	err := json.NewDecoder(r.Body).Decode(&req)
+	if err != nil && err != io.EOF {
+		resp.write(w, err)
+		return
+	}
+	_, err = h.API.CreateIndex(r.Context(), indexName, req.Options)
 
 	resp.write(w, err)
 }
@@ -647,42 +642,34 @@ func (h *Handler) handlePostField(w http.ResponseWriter, r *http.Request) {
 
 	resp := successResponse{}
 
-	err := func() error {
-		// Decode request.
-		var req postFieldRequest
-		dec := json.NewDecoder(r.Body)
-		dec.DisallowUnknownFields()
-		err := dec.Decode(&req)
-		if err == io.EOF {
-			// If no data was provided (EOF), we still create the field
-			// with default values.
-		} else if err != nil {
-			return err
-		}
+	// Decode request.
+	var req postFieldRequest
+	dec := json.NewDecoder(r.Body)
+	dec.DisallowUnknownFields()
+	err := dec.Decode(&req)
+	if err != nil && err != io.EOF {
+		resp.write(w, err)
+		return
+	}
 
-		// Validate field options.
-		if err := req.Options.validate(); err != nil {
-			return err
-		}
+	// Validate field options.
+	if err := req.Options.validate(); err != nil {
+		resp.write(w, err)
+		return
+	}
 
-		// Convert json options into functional options.
-		var fos pilosa.FieldOption
-		switch req.Options.Type {
-		case pilosa.FieldTypeSet:
-			fos = pilosa.OptFieldTypeSet(*req.Options.CacheType, *req.Options.CacheSize)
-		case pilosa.FieldTypeInt:
-			fos = pilosa.OptFieldTypeInt(*req.Options.Min, *req.Options.Max)
-		case pilosa.FieldTypeTime:
-			fos = pilosa.OptFieldTypeTime(*req.Options.TimeQuantum)
-		}
-
-		_, err = h.API.CreateField(r.Context(), indexName, fieldName, fos)
-		if err != nil {
-			return err
-		}
-		return nil
-	}()
+	// Convert json options into functional options.
+	var fos pilosa.FieldOption
+	switch req.Options.Type {
+	case pilosa.FieldTypeSet:
+		fos = pilosa.OptFieldTypeSet(*req.Options.CacheType, *req.Options.CacheSize)
+	case pilosa.FieldTypeInt:
+		fos = pilosa.OptFieldTypeInt(*req.Options.Min, *req.Options.Max)
+	case pilosa.FieldTypeTime:
+		fos = pilosa.OptFieldTypeTime(*req.Options.TimeQuantum)
+	}
 
+	_, err = h.API.CreateField(r.Context(), indexName, fieldName, fos)
 	resp.write(w, err)
 }
 

index_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/pilosa/pilosa"
 	"github.com/pilosa/pilosa/test"
+	"github.com/pkg/errors"
 )
 
 // ShardWidth is a helper reference to use when testing.
@@ -196,8 +197,8 @@ func TestIndex_DeleteField(t *testing.T) {
 
 	// Delete again to make sure it errors.
 	err := index.DeleteField("f")
-	if err == nil || err.Error() != pilosa.ErrFieldNotFound.Error() {
-		t.Fatal(err)
+	if !isNotFoundError(err) {
+		t.Fatalf("expected 'field not found' error, got: %#v", err)
 	}
 }
 
@@ -215,3 +216,9 @@ func TestIndex_InvalidName(t *testing.T) {
 		t.Fatalf("unexpected index name %v", index)
 	}
 }
+
+func isNotFoundError(err error) bool {
+	root := errors.Cause(err)
+	_, ok := root.(pilosa.NotFoundError)
+	return ok
+}

pilosa.go

@@ -71,6 +71,11 @@ type ApiMethodNotAllowedError struct {
 	error
 }
 
+// NewApiMethodNotAllowedError returns err wrapped in an ApiMethodNotAllowedError.
+func NewApiMethodNotAllowedError(err error) ApiMethodNotAllowedError {
+	return ApiMethodNotAllowedError{err}
+}
+
 // BadRequestError wraps an error value to signify that a request could not be
 // read, decoded, or parsed such that in an HTTP scenario, http.StatusBadRequest
 // would be returned.
@@ -90,12 +95,22 @@ type ConflictError struct {
 	error
 }
 
+// NewConflictError returns err wrapped in a ConflictError.
+func NewConflictError(err error) ConflictError {
+	return ConflictError{err}
+}
+
 // NotFoundError wraps an error value to signify that a resource was not found
 // such that in an HTTP scenario, http.StatusNotFound would be returned.
 type NotFoundError struct {
 	error
 }
 
+// NewNotFoundError returns err wrapped in a NotFoundError.
+func NewNotFoundError(err error) NotFoundError {
+	return NotFoundError{err}
+}
+
 // Regular expression to validate index and field names.
 var nameRegexp = regexp.MustCompile(`^[a-z][a-z0-9_-]{0,63}$`)