Add DecodeResponse and *Response.Valid() for fine-grained parse control

response.go

@@ -187,6 +187,7 @@ const guessVersionCheckBytes = 1024
 
 // Defaults to XML if it can't determine the version or if there is any
 // ambiguity
+// Returns false for SGML, true (for XML) otherwise.
 func guessVersion(r *bufio.Reader) (bool, error) {
 	b, _ := r.Peek(guessVersionCheckBytes)
 	if b == nil {
@@ -236,14 +237,13 @@ func decodeMessageSet(d *xml.Decoder, start xml.StartElement, msgs *[]Message, v
 	if !ok {
 		return errors.New("Invalid message set: " + start.Name.Local)
 	}
-	var errs ErrInvalid
 	for {
 		tok, err := nextNonWhitespaceToken(d)
 		if err != nil {
 			return err
 		} else if end, ok := tok.(xml.EndElement); ok && end.Name.Local == start.Name.Local {
 			// If we found the end of our starting element, we're done parsing
-			return errs.ErrOrNil()
+			return nil
 		} else if startElement, ok := tok.(xml.StartElement); ok {
 			responseType, ok := setTypes[startElement.Name.Local]
 			if !ok {
@@ -258,9 +258,6 @@ func decodeMessageSet(d *xml.Decoder, start xml.StartElement, msgs *[]Message, v
 			if err := d.DecodeElement(responseMessage, &startElement); err != nil {
 				return err
 			}
-			if ok, err := responseMessage.Valid(version); !ok {
-				errs.AddErr(err)
-			}
 			*msgs = append(*msgs, responseMessage)
 		} else {
 			return errors.New("Didn't find an opening element")
@@ -268,14 +265,25 @@ func decodeMessageSet(d *xml.Decoder, start xml.StartElement, msgs *[]Message, v
 	}
 }
 
-// ParseResponse parses an OFX response in SGML or XML into a Response object
-// from the given io.Reader
+// ParseResponse parses and validates an OFX response in SGML or XML into a
+// Response object from the given io.Reader
 //
 // It is commonly used as part of Client.Request(), but may be used on its own
 // to parse already-downloaded OFX files (such as those from 'Web Connect'). It
 // performs version autodetection if it can and attempts to be as forgiving as
 // possible about the input format.
 func ParseResponse(reader io.Reader) (*Response, error) {
+	resp, err := DecodeResponse(reader)
+	if err != nil {
+		return nil, err
+	}
+	_, err = resp.Valid()
+	return resp, err
+}
+
+// DecodeResponse parses an OFX response in SGML or XML into a Response object
+// from the given io.Reader
+func DecodeResponse(reader io.Reader) (*Response, error) {
 	var or Response
 
 	r := bufio.NewReaderSize(reader, guessVersionCheckBytes)
@@ -326,17 +334,12 @@ func ParseResponse(reader io.Reader) (*Response, error) {
 		return nil, errors.New("Missing opening SIGNONMSGSRSV1 xml element")
 	}
 
-	var errs ErrInvalid
-
 	tok, err = nextNonWhitespaceToken(decoder)
 	if err != nil {
 		return nil, err
 	} else if signonEnd, ok := tok.(xml.EndElement); !ok || signonEnd.Name.Local != SignonRs.String() {
 		return nil, errors.New("Missing closing SIGNONMSGSRSV1 xml element")
 	}
-	if ok, err := or.Signon.Valid(or.Version); !ok {
-		errs.AddErr(err)
-	}
 
 	var messageSlices = map[string]*[]Message{
 		SignupRs.String():     &or.Signup,
@@ -360,24 +363,53 @@ func ParseResponse(reader io.Reader) (*Response, error) {
 		if err != nil {
 			return nil, err
 		} else if ofxEnd, ok := tok.(xml.EndElement); ok && ofxEnd.Name.Local == "OFX" {
-			return &or, errs.ErrOrNil() // found closing XML element, so we're done
+			return &or, nil // found closing XML element, so we're done
 		} else if start, ok := tok.(xml.StartElement); ok {
 			slice, ok := messageSlices[start.Name.Local]
 			if !ok {
 				return nil, errors.New("Invalid message set: " + start.Name.Local)
 			}
 			if err := decodeMessageSet(decoder, start, slice, or.Version); err != nil {
-				if _, ok := err.(ErrInvalid); !ok {
 				return nil, err
 			}
-				errs.AddErr(err)
-			}
 		} else {
 			return nil, errors.New("Found unexpected token")
 		}
 	}
 }
 
+// Valid returns whether the Response is valid according to the OFX spec
+func (or *Response) Valid() (bool, error) {
+	var errs ErrInvalid
+	if ok, err := or.Signon.Valid(or.Version); !ok {
+		errs.AddErr(err)
+	}
+	for _, messageSet := range [][]Message{
+		or.Signup,
+		or.Bank,
+		or.CreditCard,
+		or.Loan,
+		or.InvStmt,
+		or.InterXfer,
+		or.WireXfer,
+		or.Billpay,
+		or.Email,
+		or.SecList,
+		or.PresDir,
+		or.PresDlv,
+		or.Prof,
+		or.Image,
+	} {
+		for _, message := range messageSet {
+			if ok, err := message.Valid(or.Version); !ok {
+				errs.AddErr(err)
+			}
+		}
+	}
+	err := errs.ErrOrNil()
+	return err == nil, err
+}
+
 // Marshal this Response into its SGML/XML representation held in a bytes.Buffer
 //
 // If error is non-nil, this bytes.Buffer is ready to be sent to an OFX client

response_test.go

@@ -177,7 +177,7 @@ func TestValidSamples(t *testing.T) {
 
 func TestInvalidResponse(t *testing.T) {
 	// in this example, the severity is invalid due to mixed upper and lower case letters
-	resp, err := ofxgo.ParseResponse(bytes.NewReader([]byte(`
+	const invalidResponse = `
 OFXHEADER:100
 DATA:OFXSGML
 VERSION:102
@@ -208,7 +208,11 @@ NEWFILEUID:NONE
 		</STMTTRNRS>
 	</BANKMSGSRSV1>
 </OFX>
-`)))
+`
+	const expectedErr = "Validation failed: Invalid STATUS>SEVERITY; Invalid STATUS>SEVERITY"
+
+	t.Run("parse response", func(t *testing.T) {
+		resp, err := ofxgo.ParseResponse(bytes.NewReader([]byte(invalidResponse)))
 		expectedErr := "Validation failed: Invalid STATUS>SEVERITY; Invalid STATUS>SEVERITY"
 		if err == nil {
 			t.Fatalf("ParseResponse should fail with %q, found nil", expectedErr)
@@ -222,6 +226,40 @@ NEWFILEUID:NONE
 		if resp == nil {
 			t.Errorf("Response must not be nil if only validation errors are present")
 		}
+	})
+
+	t.Run("parse failed", func(t *testing.T) {
+		resp, err := ofxgo.ParseResponse(bytes.NewReader(nil))
+		if err == nil {
+			t.Error("ParseResponse should fail to decode")
+		}
+		if resp != nil {
+			t.Errorf("ParseResponse should return a nil response, found: %v", resp)
+		}
+	})
+
+	t.Run("decode, then validate response", func(t *testing.T) {
+		resp, err := ofxgo.DecodeResponse(bytes.NewReader([]byte(invalidResponse)))
+		if err != nil {
+			t.Errorf("Unexpected error: %s", err.Error())
+		}
+		if resp == nil {
+			t.Fatal("Response should not be nil from successful decode")
+		}
+		valid, err := resp.Valid()
+		if valid {
+			t.Error("Response should not be valid")
+		}
+		if err == nil {
+			t.Fatalf("response.Valid() should fail with %q, found nil", expectedErr)
+		}
+		if _, ok := err.(ofxgo.ErrInvalid); !ok {
+			t.Errorf("response.Valid() should return an error of type ErrInvalid, found: %T", err)
+		}
+		if err.Error() != expectedErr {
+			t.Errorf("response.Valid() should return an error with message %q, but found %q", expectedErr, err.Error())
+		}
+	})
 }
 
 func TestErrInvalidError(t *testing.T) {