[New] add SequenceExpression

Fixes #95.

__tests__/src/getPropValue-flowparser-test.js

@@ -828,6 +828,21 @@ describe('getPropValue', () => {
     });
   });
 
+  describe('Sequence array expression', () => {
+    it('should evaluate to correct representation of the the array in props', () => {
+      const prop = extractProp('<div foo={[{"type":"Literal","start":821,"end":827}]} />');
+
+      const expected = [{
+        type: 'Literal',
+        start: 821,
+        end: 827,
+      }];
+      const actual = getPropValue(prop);
+
+      assert.deepEqual(actual, expected);
+    });
+  });
+
   describe('Array expression', () => {
     it('should evaluate to correct representation of the the array in props', () => {
       const prop = extractProp('<div foo={["bar", 42, null]} />');

src/values/expressions/SequenceExpression.js

@@ -0,0 +1,13 @@
+/**
+ * Extractor function for a SequenceExpression type value node.
+ * A Sequence expression is an object with an attribute named
+ * expressions which contains an array of different types
+ *  of expression objects.
+ *
+ * @returns - An array of the extracted elements.
+ */
+export default function extractValueFromSequenceExpression(value) {
+  // eslint-disable-next-line global-require
+  const getValue = require('.').default;
+  return value.expressions.map((element) => getValue(element));
+}

src/values/expressions/index.js

@@ -21,6 +21,7 @@ import ArrayExpression from './ArrayExpression';
 import BindExpression from './BindExpression';
 import SpreadElement from './SpreadElement';
 import TypeCastExpression from './TypeCastExpression';
+import SequenceExpression from './SequenceExpression';
 
 // Composition map of types to their extractor functions.
 const TYPES = {
@@ -48,6 +49,7 @@ const TYPES = {
   BindExpression,
   SpreadElement,
   TypeCastExpression,
+  SequenceExpression,
 };
 
 const noop = () => null;
@@ -138,6 +140,7 @@ const LITERAL_TYPES = {
   TSNonNullExpression: noop,
   TSAsExpression: noop,
   TypeCastExpression: noop,
+  SequenceExpression: noop,
 };
 
 /**