Fixed panic for ref combinations

Increased converage to >90% (more to do)
Refactored check code to improve readability and testability

Signed-off-by: Jason Wraxall <wjase@yahoo.com.au>

Author: wjase

diff/checks.go

@@ -0,0 +1,239 @@
+package diff
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/go-openapi/spec"
+)
+
+func getRef(item interface{}) spec.Ref {
+	switch s := item.(type) {
+	case *spec.Refable:
+		return s.Ref
+	case *spec.Schema:
+		return s.Ref
+	case *spec.SchemaProps:
+		return s.Ref
+	default:
+		return spec.Ref{}
+	}
+}
+
+// CheckToFromArrayType check for changes to or from an Array type
+func CheckToFromArrayType(diffs []TypeDiff, type1, type2 interface{}) []TypeDiff {
+	// Single to Array or Array to Single
+	typString1, isArray1 := getSchemaType(type1)
+	typString2, isArray2 := getSchemaType(type2)
+
+	if isArray1 != isArray2 {
+		return addTypeDiff(diffs, TypeDiff{Change: ChangedType, FromType: formatTypeString(typString1, isArray1), ToType: formatTypeString(typString2, isArray2)})
+	}
+
+	return diffs
+}
+
+// CheckToFromPrimitiveType check for diff to or from a primitive
+func CheckToFromPrimitiveType(diffs []TypeDiff, type1, type2 interface{}) []TypeDiff {
+
+	type1IsPrimitive := isPrimitive(type1)
+	type2IsPrimitive := isPrimitive(type2)
+
+	// Primitive to Obj or Obj to Primitive
+	if type1IsPrimitive != type2IsPrimitive {
+		typeStr1, isarray1 := getSchemaType(type1)
+		typeStr2, isarray2 := getSchemaType(type2)
+		return addTypeDiff(diffs, TypeDiff{Change: ChangedType, FromType: formatTypeString(typeStr1, isarray1), ToType: formatTypeString(typeStr2, isarray2)})
+	}
+
+	return diffs
+}
+
+// CheckRefChange has the property ref changed
+func CheckRefChange(diffs []TypeDiff, type1, type2 interface{}) (diffReturn []TypeDiff) {
+
+	diffReturn = diffs
+	if isRefType(type1) && isRefType(type2) {
+		// both refs but to different objects (TODO detect renamed object)
+		ref1 := definitionFromRef(getRef(type1))
+		ref2 := definitionFromRef(getRef(type2))
+		if ref1 != ref2 {
+			diffReturn = addTypeDiff(diffReturn, TypeDiff{Change: RefTargetChanged, FromType: getSchemaTypeStr(type1), ToType: getSchemaTypeStr(type2)})
+		}
+	} else {
+		if isRefType(type1) != isRefType(type2) {
+			diffReturn = addTypeDiff(diffReturn, TypeDiff{Change: ChangedType, FromType: getSchemaTypeStr(type1), ToType: getSchemaTypeStr(type2)})
+		}
+	}
+	return
+}
+
+func compareEnums(left, right []interface{}) []TypeDiff {
+	diffs := []TypeDiff{}
+
+	leftStrs := []string{}
+	rightStrs := []string{}
+	for _, eachLeft := range left {
+		leftStrs = append(leftStrs, fmt.Sprintf("%v", eachLeft))
+	}
+	for _, eachRight := range right {
+		rightStrs = append(rightStrs, fmt.Sprintf("%v", eachRight))
+	}
+	added, deleted, _ := fromStringArray(leftStrs).DiffsTo(rightStrs)
+	if len(added) > 0 {
+		typeChange := strings.Join(added, ",")
+		diffs = append(diffs, TypeDiff{Change: AddedEnumValue, Description: typeChange})
+	}
+	if len(deleted) > 0 {
+		typeChange := strings.Join(deleted, ",")
+		diffs = append(diffs, TypeDiff{Change: DeletedEnumValue, Description: typeChange})
+	}
+
+	return diffs
+}
+
+// checkNumericTypeChanges checks for changes to or from a numeric type
+func checkNumericTypeChanges(diffs []TypeDiff, type1, type2 *spec.SchemaProps) []TypeDiff {
+	// Number
+	_, type1IsNumeric := numberWideness[type1.Type[0]]
+	_, type2IsNumeric := numberWideness[type2.Type[0]]
+
+	if type1IsNumeric && type2IsNumeric {
+		foundDiff := false
+		if type1.ExclusiveMaximum && !type2.ExclusiveMaximum {
+			diffs = addTypeDiff(diffs, TypeDiff{Change: WidenedType, Description: fmt.Sprintf("Exclusive Maximum Removed:%v->%v", type1.ExclusiveMaximum, type2.ExclusiveMaximum)})
+			foundDiff = true
+		}
+		if !type1.ExclusiveMaximum && type2.ExclusiveMaximum {
+			diffs = addTypeDiff(diffs, TypeDiff{Change: NarrowedType, Description: fmt.Sprintf("Exclusive Maximum Added:%v->%v", type1.ExclusiveMaximum, type2.ExclusiveMaximum)})
+			foundDiff = true
+		}
+		if type1.ExclusiveMinimum && !type2.ExclusiveMinimum {
+			diffs = addTypeDiff(diffs, TypeDiff{Change: WidenedType, Description: fmt.Sprintf("Exclusive Minimum Removed:%v->%v", type1.ExclusiveMaximum, type2.ExclusiveMaximum)})
+			foundDiff = true
+		}
+		if !type1.ExclusiveMinimum && type2.ExclusiveMinimum {
+			diffs = addTypeDiff(diffs, TypeDiff{Change: NarrowedType, Description: fmt.Sprintf("Exclusive Minimum Added:%v->%v", type1.ExclusiveMinimum, type2.ExclusiveMinimum)})
+			foundDiff = true
+		}
+		if !foundDiff {
+			diffs = addTypeDiff(diffs, compareFloatValues("Maximum", type1.Maximum, type2.Maximum, WidenedType, NarrowedType))
+			diffs = addTypeDiff(diffs, compareFloatValues("Minimum", type1.Minimum, type2.Minimum, NarrowedType, WidenedType))
+		}
+	}
+	return diffs
+}
+
+// CheckStringTypeChanges checks for changes to or from a string type
+func CheckStringTypeChanges(diffs []TypeDiff, type1, type2 *spec.SchemaProps) []TypeDiff {
+	// string changes
+	if type1.Type[0] == StringType &&
+		type2.Type[0] == StringType {
+		diffs = addTypeDiff(diffs, compareIntValues("MinLength", type1.MinLength, type2.MinLength, NarrowedType, WidenedType))
+		diffs = addTypeDiff(diffs, compareIntValues("MaxLength", type1.MinLength, type2.MinLength, WidenedType, NarrowedType))
+		if type1.Pattern != type2.Pattern {
+			diffs = addTypeDiff(diffs, TypeDiff{Change: ChangedType, Description: fmt.Sprintf("Pattern Changed:%s->%s", type1.Pattern, type2.Pattern)})
+		}
+		if type1.Type[0] == StringType {
+			if len(type1.Enum) > 0 {
+				enumDiffs := compareEnums(type1.Enum, type2.Enum)
+				diffs = append(diffs, enumDiffs...)
+			}
+		}
+	}
+	return diffs
+}
+
+// CheckToFromRequired checks for changes to or from a required property
+func CheckToFromRequired(required1, required2 bool) (diffs []TypeDiff) {
+	if required1 != required2 {
+		code := AddedRequiredProperty
+		if required1 {
+			code = ChangedRequiredToOptional
+		}
+		diffs = addTypeDiff(diffs, TypeDiff{Change: code})
+	}
+	return diffs
+}
+
+func compareProperties(location DifferenceLocation, schema1 *spec.Schema, schema2 *spec.Schema, getRefFn1 SchemaFromRefFn, getRefFn2 SchemaFromRefFn, cmp CompareSchemaFn) []SpecDifference {
+	propDiffs := []SpecDifference{}
+
+	requiredProps2 := sliceToStrMap(schema2.Required)
+	requiredProps1 := sliceToStrMap(schema1.Required)
+	schema1Props := propertiesFor(schema1, getRefFn1)
+	schema2Props := propertiesFor(schema2, getRefFn2)
+	// find deleted and changed properties
+
+	for eachProp1Name, eachProp1 := range schema1Props {
+		eachProp1 := eachProp1
+		_, required1 := requiredProps1[eachProp1Name]
+		_, required2 := requiredProps2[eachProp1Name]
+		childLoc := addChildDiffNode(location, eachProp1Name, &eachProp1)
+
+		if eachProp2, ok := schema2Props[eachProp1Name]; ok {
+			diffs := CheckToFromRequired(required1, required2)
+			if len(diffs) > 0 {
+				for _, diff := range diffs {
+					propDiffs = append(propDiffs, SpecDifference{DifferenceLocation: childLoc, Code: diff.Change})
+				}
+			}
+			cmp(childLoc, &eachProp1, &eachProp2)
+		} else {
+			propDiffs = append(propDiffs, SpecDifference{DifferenceLocation: childLoc, Code: DeletedProperty})
+		}
+	}
+
+	// find added properties
+	for eachProp2Name, eachProp2 := range schema2.Properties {
+		if _, ok := schema1.Properties[eachProp2Name]; !ok {
+			childLoc := addChildDiffNode(location, eachProp2Name, &eachProp2)
+			propDiffs = append(propDiffs, SpecDifference{DifferenceLocation: childLoc, Code: AddedProperty})
+		}
+	}
+	return propDiffs
+
+}
+
+// SchemaFromRefFn define this to get a schema for a ref
+type SchemaFromRefFn func(spec.Ref) (*spec.Schema, string)
+
+func propertiesFor(schema *spec.Schema, getRefFn SchemaFromRefFn) PropertyMap {
+	schemaFromRef, _ := getRefFn(schema.Ref)
+	if schemaFromRef != nil {
+		schema = schemaFromRef
+	}
+	props := PropertyMap{}
+
+	if schema.Properties != nil {
+		for name, prop := range schema.Properties {
+			props[name] = prop
+		}
+	}
+	for _, eachAllOf := range schema.AllOf {
+		eachAllOf := eachAllOf
+		eachAllOfActual, _ := getRefFn(eachAllOf.SchemaProps.Ref)
+		if eachAllOfActual == nil {
+			eachAllOfActual = &eachAllOf
+		}
+		for name, prop := range eachAllOfActual.Properties {
+			props[name] = prop
+		}
+	}
+	return props
+}
+
+func isRefType(item interface{}) bool {
+	switch s := item.(type) {
+	case spec.Refable:
+		return s.Ref.String() != ""
+	case *spec.Schema:
+		return s.Ref.String() != ""
+	case *spec.SchemaProps:
+		return s.Ref.String() != ""
+	case *spec.SimpleSchema:
+		return false
+	default:
+		return false
+	}
+}