Fix parsing of single item array replacements

array_attribute.go

@@ -18,21 +18,24 @@ var _ attributeChange = &ArrayAttributeChange{}
 
 // IsArrayAttributeChangeLine returns true if the line is a valid attribute change
 // This requires the line to start with "+", "-" or "~", not be followed with "resource" or "data", and ends with "[".
+// Terraform may append ForcesReplacementComment after the opening bracket.
 func IsArrayAttributeChangeLine(line string) bool {
 	line = strings.TrimSpace(line)
-	// validPrefix := strings.HasPrefix(line, "+") || strings.HasPrefix(line, "-") || strings.HasPrefix(line, "~")
-	validSuffix := strings.HasSuffix(line, "[") || IsOneLineEmptyArrayAttribute(line)
+	base := strings.TrimSpace(strings.TrimSuffix(line, ForcesReplacementComment))
+	validSuffix := strings.HasSuffix(base, "[") || IsOneLineEmptyArrayAttribute(line)
 	return validSuffix && !IsResourceChangeLine(line)
 }
 
 // IsArrayAttributeTerminator returns true if the line is "]" or "] -> null"
 func IsArrayAttributeTerminator(line string) bool {
-	return strings.TrimSuffix(strings.TrimSpace(line), " -> null") == "]"
+	return strings.TrimSuffix(strings.TrimSpace(line), " -> null") == "]" || strings.TrimSuffix(strings.TrimSpace(line), " -> (known after apply)") == "]"
 }
 
 // IsOneLineEmptyArrayAttribute returns true if the line ends with a "[]"
 func IsOneLineEmptyArrayAttribute(line string) bool {
-	return strings.HasSuffix(line, "[]")
+	line = strings.TrimSpace(line)
+	line = strings.TrimSuffix(line, ForcesReplacementComment)
+	return strings.HasSuffix(strings.TrimSpace(line), "[]")
 }
 
 // NewArrayAttributeChangeFromLine initializes an ArrayAttributeChange from a line containing an array attribute change
@@ -57,10 +60,13 @@ func NewArrayAttributeChangeFromLine(line string) (*ArrayAttributeChange, error)
 			UpdateType: DestroyResource,
 		}, nil
 	} else if strings.HasPrefix(line, "~") {
-		// replace
+		updateType := UpdateInPlaceResource
+		if strings.HasSuffix(strings.TrimSpace(line), ForcesReplacementComment) {
+			updateType = ForceReplaceResource
+		}
 		return &ArrayAttributeChange{
 			Name:       attributeName,
-			UpdateType: UpdateInPlaceResource,
+			UpdateType: updateType,
 		}, nil
 	} else {
 		return &ArrayAttributeChange{

array_attribute_test.go

@@ -64,6 +64,14 @@ func TestNewArrayAttributeChangeFromLine(t *testing.T) {
 				UpdateType: UpdateInPlaceResource,
 			},
 		},
+		"attribute changed forces replacement": {
+			line:        `~ array_test = [` + ForcesReplacementComment,
+			shouldError: false,
+			expected: &ArrayAttributeChange{
+				Name:       "array_test",
+				UpdateType: ForceReplaceResource,
+			},
+		},
 		"attribute is unchanged": {
 			line:        `attribute [`,
 			shouldError: false,

attribute.go

@@ -11,6 +11,8 @@ const (
 	ATTRIBUTE_DEFINITON_DELIMITER = " = "
 	SENSITIVE_VALUE               = "(sensitive value)"
 	COMPUTED_VALUE                = "(known after apply)"
+	// ForcesReplacementComment is the suffix Terraform appends to attributes that trigger replace.
+	ForcesReplacementComment = " # forces replacement"
 )
 
 type attributeChange interface {
@@ -92,9 +94,9 @@ func NewAttributeChangeFromLine(line string) (*AttributeChange, error) {
 		// replace
 		updateType := UpdateInPlaceResource
 
-		if strings.HasSuffix(attribute[1], " # forces replacement") {
+		if strings.HasSuffix(attribute[1], ForcesReplacementComment) {
 			updateType = ForceReplaceResource
-			attribute[1] = strings.TrimSuffix(attribute[1], " # forces replacement")
+			attribute[1] = strings.TrimSuffix(attribute[1], ForcesReplacementComment)
 		}
 
 		values := strings.Split(attribute[1], ATTRIBUTE_CHANGE_DELIMITER)
@@ -112,11 +114,18 @@ func NewAttributeChangeFromLine(line string) (*AttributeChange, error) {
 			UpdateType: updateType,
 		}, nil
 	} else {
+		valStr := strings.TrimSpace(attribute[1])
+		updateType := NoOpResource
+		if strings.HasSuffix(valStr, ForcesReplacementComment) {
+			valStr = strings.TrimSpace(strings.TrimSuffix(valStr, ForcesReplacementComment))
+			updateType = ForceReplaceResource
+		}
+		conv := doTypeConversion(valStr)
 		return &AttributeChange{
 			Name:       dequote(strings.TrimSpace(attribute[0])),
-			OldValue:   doTypeConversion(attribute[1]),
-			NewValue:   doTypeConversion(attribute[1]),
-			UpdateType: NoOpResource,
+			OldValue:   conv,
+			NewValue:   conv,
+			UpdateType: updateType,
 		}, nil
 	}
 }
@@ -143,9 +152,15 @@ func NewAttributeChangeFromArray(line string) (*AttributeChange, error) {
 			UpdateType: DestroyResource,
 		}, nil
 	} else if strings.HasPrefix(line, "~") {
-		// replace
-		// TODO: confirm this is possible? I think array entries are immutable
-		return nil, fmt.Errorf("unexpected replace single attribute in array %s", line)
+		parts := strings.Split(line, ATTRIBUTE_CHANGE_DELIMITER)
+		if len(parts) != 2 {
+			return nil, fmt.Errorf("unexpected replace single attribute in array %s", line)
+		}
+		return &AttributeChange{
+			OldValue:   normalizeArrayAttribute(parts[0]),
+			NewValue:   normalizeArrayAttribute(parts[1]),
+			UpdateType: UpdateInPlaceResource,
+		}, nil
 	} else {
 		return &AttributeChange{
 			OldValue:   normalizeArrayAttribute(line),

attribute_test.go

@@ -171,6 +171,16 @@ func TestNewAttributeChangeFromLine(t *testing.T) {
 				UpdateType: NoOpResource,
 			},
 		},
+		"unchanged attribute forces replacement": {
+			line:        `id = "namespace-id"` + ForcesReplacementComment,
+			shouldError: false,
+			expected: &AttributeChange{
+				Name:       "id",
+				OldValue:   "namespace-id",
+				NewValue:   "namespace-id",
+				UpdateType: ForceReplaceResource,
+			},
+		},
 		"resource line": {
 			line:        `+ resource "type" "name" {`,
 			shouldError: true,
@@ -294,6 +304,15 @@ func TestNewAttributeChangeFromArray(t *testing.T) {
 				UpdateType: NewResource,
 			},
 		},
+		"array item swapped": {
+			line:        `~ "old" -> "new"`,
+			shouldError: false,
+			expected: &AttributeChange{
+				OldValue:   "old",
+				NewValue:   "new",
+				UpdateType: UpdateInPlaceResource,
+			},
+		},
 		"other line": {
 			line:        `}`,
 			shouldError: true,

heredoc_attribute.go

@@ -65,7 +65,7 @@ func NewHeredocAttributeChangeFromLine(line string) (*HeredocAttributeChange, er
 	} else if strings.HasPrefix(line, "~") {
 		// replace
 		updateType := UpdateInPlaceResource
-		if strings.HasSuffix(attribute[1], " # forces replacement") {
+		if strings.HasSuffix(attribute[1], ForcesReplacementComment) {
 			updateType = ForceReplaceResource
 		}
 

jsonencode.go

@@ -57,7 +57,7 @@ func NewJSONEncodeAttributeChangeFromLine(line string) (*JSONEncodeAttributeChan
 	} else if strings.HasPrefix(line, "~") {
 		// replace
 		updateType := UpdateInPlaceResource
-		if strings.HasSuffix(attribute[1], " # forces replacement") {
+		if strings.HasSuffix(attribute[1], ForcesReplacementComment) {
 			updateType = ForceReplaceResource
 		}
 

map_attribute.go

@@ -15,21 +15,24 @@ var _ attributeChange = &MapAttributeChange{}
 
 // IsMapAttributeChangeLine returns true if the line is a valid attribute change
 // This requires the line to start with "+", "-" or "~", not be followed with "resource" or "data", and ends with "{".
+// Terraform may append ForcesReplacementComment after the opening brace.
 func IsMapAttributeChangeLine(line string) bool {
 	line = strings.TrimSpace(line)
-	// validPrefix := strings.HasPrefix(line, "+") || strings.HasPrefix(line, "-") || strings.HasPrefix(line, "~")
-	validSuffix := strings.HasSuffix(line, "{") || IsOneLineEmptyMapAttribute(line)
+	base := strings.TrimSpace(strings.TrimSuffix(line, ForcesReplacementComment))
+	validSuffix := strings.HasSuffix(base, "{") || IsOneLineEmptyMapAttribute(line)
 	return validSuffix && !IsResourceChangeLine(line)
 }
 
 // IsMapAttributeTerminator returns true if the line is a "}" or "},"
 func IsMapAttributeTerminator(line string) bool {
-	return strings.TrimSuffix(strings.TrimSuffix(strings.TrimSpace(line), ","), " -> null") == "}"
+	return strings.TrimSuffix(strings.TrimSuffix(strings.TrimSpace(line), ","), " -> null") == "}" || strings.TrimSuffix(strings.TrimSuffix(strings.TrimSpace(line), ","), " -> (known after apply)") == "}"
 }
 
 // IsOneLineEmptyMapAttribute returns true if the line ends with a "{}"
 func IsOneLineEmptyMapAttribute(line string) bool {
-	return strings.HasSuffix(line, "{}")
+	line = strings.TrimSpace(line)
+	line = strings.TrimSuffix(line, ForcesReplacementComment)
+	return strings.HasSuffix(strings.TrimSpace(line), "{}")
 }
 
 // NewMapAttributeChangeFromLine initializes an AttributeChange from a line containing an attribute change
@@ -54,10 +57,13 @@ func NewMapAttributeChangeFromLine(line string) (*MapAttributeChange, error) {
 			UpdateType: DestroyResource,
 		}, nil
 	} else if strings.HasPrefix(line, "~") {
-		// replace
+		updateType := UpdateInPlaceResource
+		if strings.HasSuffix(strings.TrimSpace(line), ForcesReplacementComment) {
+			updateType = ForceReplaceResource
+		}
 		return &MapAttributeChange{
 			Name:       attributeName,
-			UpdateType: UpdateInPlaceResource,
+			UpdateType: updateType,
 		}, nil
 	} else {
 		return &MapAttributeChange{

map_attribute_test.go

@@ -64,6 +64,14 @@ func TestNewMapAttributeChangeFromLine(t *testing.T) {
 				UpdateType: UpdateInPlaceResource,
 			},
 		},
+		"attribute changed forces replacement": {
+			line:        `~ triggers = {` + ForcesReplacementComment,
+			shouldError: false,
+			expected: &MapAttributeChange{
+				Name:       "triggers",
+				UpdateType: ForceReplaceResource,
+			},
+		},
 		"attribute is unchanged": {
 			line:        `attribute {`,
 			shouldError: false,