Allow constraints when JSON body is an array

Previously, a JSON request body being an array was a special-case. Now that arrays are handled nested within the JSON body, treat them as any other JSON. The constraints will now get correctly added as with any other value.

Author: joshkeegan-form3

internal/app/pactproxy/interaction.go

@@ -117,18 +117,8 @@ func LoadInteraction(data []byte, alias string) (*Interaction, error) {
 
 	switch mediaType {
 	case mediaTypeJSON:
-		if jsonRequestBody, ok := requestBody.(map[string]interface{}); ok {
-			interaction.addJSONConstraintsFromPact("$.body", propertiesWithMatchingRule, jsonRequestBody)
-			return interaction, nil
-		}
-
-		if _, ok := requestBody.([]interface{}); ok {
-			// An array request body should be accepted for application/json media type.
-			// However, no constraint is added for it
-			return interaction, nil
-		}
-
-		return nil, fmt.Errorf("media type is %s but body is not json", mediaType)
+		interaction.addJSONConstraintsFromPact("$.body", propertiesWithMatchingRule, requestBody)
+		return interaction, nil
 	case mediaTypeText, mediaTypeCsv, mediaTypeXml:
 		if body, ok := requestBody.(string); ok {
 			interaction.addTextConstraintsFromPact(propertiesWithMatchingRule, body)
@@ -271,29 +261,24 @@ func parseMediaType(request map[string]interface{}) (string, error) {
 
 // This function adds constraints for all the fields in the JSON request body which do not
 // have a corresponding matching rule
-func (i *Interaction) addJSONConstraintsFromPact(path string, matchingRules map[string]bool, values map[string]interface{}) {
-	for k, v := range values {
-		i.addJSONConstraintsFromPactAny(path+"."+k, matchingRules, v)
-	}
-}
-
-func (i *Interaction) addJSONConstraintsFromPactAny(path string, matchingRules map[string]bool, value interface{}) {
+func (i *Interaction) addJSONConstraintsFromPact(path string, matchingRules map[string]bool, value interface{}) {
 	if _, hasRule := matchingRules[path]; hasRule {
 		return
 	}
-
 	switch val := value.(type) {
 	case map[string]interface{}:
 		// json_class is used to test for a Pact DSL-style matching rule within the body. The matchingRules passed
 		// to this method will not include these.
 		if _, exists := val["json_class"]; exists {
 			return
 		}
-		i.addJSONConstraintsFromPact(path, matchingRules, val)
+		for k, v := range val {
+			i.addJSONConstraintsFromPact(path+"."+k, matchingRules, v)
+		}
 	case []interface{}:
 		// Create constraints for each element in the array. This allows matching rules to override them.
 		for j := range val {
-			i.addJSONConstraintsFromPactAny(fmt.Sprintf("%s[%d]", path, j), matchingRules, val[j])
+			i.addJSONConstraintsFromPact(fmt.Sprintf("%s[%d]", path, j), matchingRules, val[j])
 		}
 		// Length constraint so that requests with additional elements at the end of the array will not match
 		i.AddConstraint(interactionConstraint{

internal/app/pactproxy/interaction_test.go

@@ -121,7 +121,7 @@ func TestLoadInteractionPlainTextConstraints(t *testing.T) {
 }
 
 func TestLoadInteractionJSONConstraints(t *testing.T) {
-	arrMatchersNotPresent := `{
+	nestedArrMatchersNotPresent := `{
 		"description": "A request to create an address",
 		"request": {
 		  "method": "POST",
@@ -143,7 +143,7 @@ func TestLoadInteractionJSONConstraints(t *testing.T) {
 		  }
 		}
 	  }`
-	arrMatcherPresent :=
+	nestedArrMatcherPresent :=
 		`{
 		"description": "A request to create an address",
 		"request": {
@@ -171,14 +171,50 @@ func TestLoadInteractionJSONConstraints(t *testing.T) {
 		  }
 		}
 	  }`
+	arrayOfStrings := `{
+		"description": "A request to create an address",
+		"request": {
+		  "method": "POST",
+		  "path": "/addresses",
+		  "headers": {
+			"Content-Type": "application/json"
+		  },
+		  "body": ["line 1", "line 2"]
+		},
+		"response": {
+		  "status": 200,
+		  "headers": {
+			"Content-Type": "application/json"
+		  },
+		  "body": ["line 1", "line 2"]
+		}
+	  }`
+	arrayOfObjects := `{
+		"description": "A request to create an address",
+		"request": {
+			"method": "POST",
+			"path": "/addresses",
+			"headers": {
+			"Content-Type": "application/json"
+			},
+			"body": [ {"key": "val"}, {"key": "val"} ]
+		},
+		"response": {
+			"status": 200,
+			"headers": {
+			"Content-Type": "application/json"
+			},
+			"body": [ {"key": "val"}, {"key": "val"} ]
+		}
+	  }`
 	tests := []struct {
 		name            string
 		interaction     []byte
 		wantConstraints []interactionConstraint
 	}{
 		{
-			name:        "array and matcher not present - interactions are created per element",
-			interaction: []byte(arrMatchersNotPresent),
+			name:        "nested array and matcher not present - interactions are created per element",
+			interaction: []byte(nestedArrMatchersNotPresent),
 			wantConstraints: []interactionConstraint{
 				{
 					Path:   "$.body.addressLines[0]",
@@ -198,8 +234,8 @@ func TestLoadInteractionJSONConstraints(t *testing.T) {
 			},
 		},
 		{
-			name:        "array and matcher present - interaction is not created for matched element",
-			interaction: []byte(arrMatcherPresent),
+			name:        "nested array and matcher present - interaction is not created for matched element",
+			interaction: []byte(nestedArrMatcherPresent),
 			wantConstraints: []interactionConstraint{
 				{
 					Path:   "$.body.addressLines[1]",
@@ -213,6 +249,48 @@ func TestLoadInteractionJSONConstraints(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:        "body array and matcher not present - interactions are created per element",
+			interaction: []byte(arrayOfStrings),
+			wantConstraints: []interactionConstraint{
+				{
+					Path:   "$.body[0]",
+					Format: "%v",
+					Values: []interface{}{"line 1"},
+				},
+				{
+					Path:   "$.body[1]",
+					Format: "%v",
+					Values: []interface{}{"line 2"},
+				},
+				{
+					Path:   "$.body",
+					Format: fmtLen,
+					Values: []interface{}{2},
+				},
+			},
+		},
+		{
+			name:        "body array of objects - interactions are created per element",
+			interaction: []byte(arrayOfObjects),
+			wantConstraints: []interactionConstraint{
+				{
+					Path:   "$.body[0].key",
+					Format: "%v",
+					Values: []interface{}{"val"},
+				},
+				{
+					Path:   "$.body[1].key",
+					Format: "%v",
+					Values: []interface{}{"val"},
+				},
+				{
+					Path:   "$.body",
+					Format: fmtLen,
+					Values: []interface{}{2},
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -362,140 +440,6 @@ func TestV3MatchingRulesLeadToCorrectConstraints(t *testing.T) {
 	}
 }
 
-func TestLoadArrayRequestBodyInteractions(t *testing.T) {
-	arrayOfStrings := `{
-		"description": "A request to create an address",
-		"request": {
-		  "method": "POST",
-		  "path": "/addresses",
-		  "headers": {
-			"Content-Type": "application/json"
-		  },
-		  "body": ["a", "b", "c"]
-		},
-		"response": {
-		  "status": 200,
-		  "headers": {
-			"Content-Type": "application/json"
-		  },
-		  "body": ["a", "b", "c"]
-		}
-	  }`
-	arrayOfInts := `{
-		"description": "A request to create an address",
-		"request": {
-			"method": "POST",
-			"path": "/addresses",
-			"headers": {
-			"Content-Type": "application/json"
-			},
-			"body": [1, 2, 3]
-		},
-		"response": {
-			"status": 200,
-			"headers": {
-			"Content-Type": "application/json"
-			},
-			"body": [1, 2, 3]
-		}
-		}`
-	arrayOfBools := `{
-			"description": "A request to create an address",
-			"request": {
-				"method": "POST",
-				"path": "/addresses",
-				"headers": {
-				"Content-Type": "application/json"
-				},
-				"body": [true, false, true]
-			},
-			"response": {
-				"status": 200,
-				"headers": {
-				"Content-Type": "application/json"
-				},
-				"body": [true, false, true]
-			}
-			}`
-	arrayOfObjects := `{
-			"description": "A request to create an address",
-			"request": {
-				"method": "POST",
-				"path": "/addresses",
-				"headers": {
-				"Content-Type": "application/json"
-				},
-				"body": [ {"key": "val"}, {"key": "val"} ]
-			},
-			"response": {
-				"status": 200,
-				"headers": {
-				"Content-Type": "application/json"
-				},
-				"body": [ {"key": "val"}, {"key": "val"} ]
-			}
-			}`
-	arrayOfStringsWithMatcher :=
-		`{
-		"description": "A request to create an address",
-		"request": {
-		  "method": "POST",
-		  "path": "/addresses",
-			"headers": {
-			"Content-Type": "application/json"
-		  },
-		  "body": ["a", "b", "c"],
-		  "matchingRules": {
-				"$.body": {
-					"match": "type"
-				}
-			}
-		},
-		"response": {
-		  "status": 200,
-		  "headers": {
-			"Content-Type": "application/json"
-			},
-			"body": ["a", "b", "c"]
-		}
-	  }`
-
-	tests := []struct {
-		name        string
-		interaction []byte
-	}{
-		{
-			name:        "array of strings",
-			interaction: []byte(arrayOfStrings),
-		},
-		{
-			name:        "array of ints",
-			interaction: []byte(arrayOfInts),
-		},
-		{
-			name:        "array of bools",
-			interaction: []byte(arrayOfBools),
-		},
-		{
-			name:        "array of objects",
-			interaction: []byte(arrayOfObjects),
-		},
-		{
-			name:        "array of strings with matcher",
-			interaction: []byte(arrayOfStringsWithMatcher),
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			interaction, err := LoadInteraction(tt.interaction, "alias")
-			require.NoError(t, err, "unexpected error %v", err)
-
-			require.Empty(t, interaction.constraints, "No constraint should be added for the interaction")
-		})
-	}
-}
-
 func Test_parseMediaType(t *testing.T) {
 	tests := []struct {
 		name    string

internal/app/proxy_test.go

@@ -559,7 +559,6 @@ func TestArrayBodyRequest(t *testing.T) {
 				the_response_body_is(tc.respBody)
 		})
 	}
-
 }
 
 func TestArrayBodyRequestWithModifiedStatusCode(t *testing.T) {
@@ -594,9 +593,9 @@ func TestArrayBodyRequestUnmatchedRequestBody(t *testing.T) {
 				a_request_is_sent_with("application/json", tc.unmatchedReqBody)
 
 			then.
-				// Pact Mock Server returns 500 if request body does not match
+				// Pact Proxy returns 400 if request body does not match
 				pact_verification_is_not_successful().and().
-				the_response_is_(http.StatusInternalServerError)
+				the_response_is_(http.StatusBadRequest)
 		})
 	}
 }