Audit code for consistency with checkpoint #1 of the architecture plan

internal/core/source/validation.go

@@ -12,6 +12,9 @@ func ValidateDocument(doc *SourceDocument) error {
 	if isBlank(doc.ID) {
 		return fmt.Errorf("source document id must not be empty")
 	}
+	if hasSurroundingWhitespace(doc.ID) {
+		return fmt.Errorf("source document id %q must not contain leading or trailing whitespace", doc.ID)
+	}
 	if isBlank(doc.Kind) {
 		return fmt.Errorf("source document kind must not be empty")
 	}
@@ -27,20 +30,22 @@ func ValidateDocument(doc *SourceDocument) error {
 
 	seenUnitIDs := make(map[string]struct{}, len(doc.Units))
 	for i, unit := range doc.Units {
-		unitID := strings.TrimSpace(unit.ID)
-		if unitID == "" {
+		if isBlank(unit.ID) {
 			return fmt.Errorf("source unit[%d].id must not be empty", i)
 		}
+		if hasSurroundingWhitespace(unit.ID) {
+			return fmt.Errorf("source unit[%d].id %q must not contain leading or trailing whitespace", i, unit.ID)
+		}
 		if isBlank(unit.Kind) {
 			return fmt.Errorf("source unit[%d].kind must not be empty", i)
 		}
 		if isBlank(unit.Text) {
 			return fmt.Errorf("source unit[%d].text must not be empty", i)
 		}
-		if _, ok := seenUnitIDs[unitID]; ok {
-			return fmt.Errorf("source unit id %q is duplicated", unitID)
+		if _, ok := seenUnitIDs[unit.ID]; ok {
+			return fmt.Errorf("source unit id %q is duplicated", unit.ID)
 		}
-		seenUnitIDs[unitID] = struct{}{}
+		seenUnitIDs[unit.ID] = struct{}{}
 	}
 
 	return nil
@@ -53,12 +58,21 @@ func ValidateRef(doc *SourceDocument, ref SourceRef) error {
 	if isBlank(ref.SourceID) {
 		return fmt.Errorf("source ref source_id must not be empty")
 	}
+	if hasSurroundingWhitespace(ref.SourceID) {
+		return fmt.Errorf("source ref source_id %q must not contain leading or trailing whitespace", ref.SourceID)
+	}
 	if isBlank(ref.StartUnitID) {
 		return fmt.Errorf("source ref start_unit_id must not be empty")
 	}
+	if hasSurroundingWhitespace(ref.StartUnitID) {
+		return fmt.Errorf("source ref start_unit_id %q must not contain leading or trailing whitespace", ref.StartUnitID)
+	}
 	if isBlank(ref.EndUnitID) {
 		return fmt.Errorf("source ref end_unit_id must not be empty")
 	}
+	if hasSurroundingWhitespace(ref.EndUnitID) {
+		return fmt.Errorf("source ref end_unit_id %q must not contain leading or trailing whitespace", ref.EndUnitID)
+	}
 	if ref.SourceID != doc.ID {
 		return fmt.Errorf("source ref source_id %q does not match document id %q", ref.SourceID, doc.ID)
 	}
@@ -93,3 +107,7 @@ func UnitIndex(doc *SourceDocument, unitID string) (int, bool) {
 func isBlank(value string) bool {
 	return strings.TrimSpace(value) == ""
 }
+
+func hasSurroundingWhitespace(value string) bool {
+	return strings.TrimSpace(value) != value
+}