issue-281: add tests and fix panic for *

Signed-off-by: ivan katliarchuk <ivan.katliarchuk@gmail.com>

.gitignore

@@ -1,2 +1,4 @@
 bin/
 cover.out
+.DS_Store
+.idea/

ast/ast.go

@@ -1598,6 +1598,9 @@ func (n *SequenceNode) blockStyleString() string {
 	}
 
 	for idx, value := range n.Values {
+		if value == nil {
+			continue
+		}
 		valueStr := value.String()
 		newLinePrefix := ""
 		if strings.HasPrefix(valueStr, "\n") {

path_test.go

@@ -84,6 +84,36 @@ store:
 			path:     builder().Root().Child("store").Child("book").IndexAll().Child("author").Build(),
 			expected: []interface{}{"john", "ken"},
 		},
+		{
+			name: "$.store.book[*]",
+			path: builder().Root().Child("store").Child("book").IndexAll().Build(),
+			expected: []interface{}{
+				map[string]interface{}{
+					"author": "john",
+					"price":  uint64(10),
+				},
+				map[string]interface{}{
+					"author": "ken",
+					"price":  uint64(12),
+				},
+			},
+		},
+		{
+			name: "$..book[*]",
+			path: builder().Root().Recursive("book").IndexAll().Build(),
+			expected: []interface{}{
+				[]interface{}{
+					map[string]interface{}{
+						"author": "john",
+						"price":  uint64(10),
+					},
+					map[string]interface{}{
+						"author": "ken",
+						"price":  uint64(12),
+					},
+				},
+			},
+		},
 		{
 			name:     "$.store.book[0]",
 			path:     builder().Root().Child("store").Child("book").Index(0).Build(),
@@ -305,6 +335,143 @@ func TestPath_Invalid(t *testing.T) {
 	}
 }
 
+func TestPath_ReadNode(t *testing.T) {
+	tests := []struct {
+		name     string
+		path     string
+		src      string
+		expected interface{}
+	}{
+		{
+			name: "nested array sequence",
+			path: `$.a.b[0].c`,
+			src: `
+a:
+  b:
+   - c: 123
+  e: |
+   Line1
+   Line2
+`,
+			expected: uint64(123),
+		},
+		{
+			name: "nested array sequence issue#281",
+			path: `$..a.c`,
+			src: `
+s:
+  - a:
+      b: u1
+      c: get1
+      d: i1
+  - w:
+      c: bad
+      e:
+        - a:
+           b: u2
+           c: get2
+           d: i2
+`,
+			// The expected values are
+			// - get1
+			// - get2
+			expected: []interface{}{
+				map[string]interface{}{
+					"b": "u1",
+					"c": "get1",
+					"d": "i1",
+				},
+				map[string]interface{}{
+					"b": "u2",
+					"c": "get2",
+					"d": "i2",
+				},
+			},
+		},
+		{
+			name: "nested array sequence issue#281",
+			path: `$..c`,
+			src: `
+s:
+  - a:
+      b: u1
+      c: get1
+      d: i1
+  - w:
+      c: bad
+      e:
+        - a:
+            b: u2
+            c: get2
+            d: i2
+`,
+			expected: []interface{}{"get1", "bad", "get2"},
+		},
+		{
+			name: "nested array sequence issue#281",
+			path: `$.s[0].a.c`,
+			src: `
+s:
+  - a:
+      b: u1
+      c: get1
+      d: i1
+  - w:
+      c: bad
+      e:
+        - a:
+            b: u2
+            c: get2
+            d: i2
+`,
+			expected: "get1",
+		},
+		{
+			name: "nested array sequence issue#281",
+			path: "$.s[*].a.c",
+			src: `
+s:
+  - a:
+      b: u1
+      c: get1
+      d: i1
+  - w:
+      c: bad
+      e:
+        - a:
+            b: u2
+            c: get2
+            d: i2
+`,
+			expected: []interface{}{"get1"},
+		},
+	}
+	for _, test := range tests {
+		path, err := yaml.PathString(test.path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Run(fmt.Sprintf("path.ReadNode %s path %s", test.name, test.path), func(t *testing.T) {
+			file, err := parser.ParseBytes([]byte(test.src), 0)
+			if err != nil {
+				t.Fatal(err)
+			}
+			n, err := path.ReadNode(file)
+			if err != nil {
+				t.Fatal("expected error", err)
+			}
+			var v interface{}
+			err = yaml.Unmarshal([]byte(n.String()), &v)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if !reflect.DeepEqual(test.expected, v) {
+				t.Fatalf("expected %v(%T) but got %v(%T)", test.expected, test.expected, v, v)
+			}
+		})
+	}
+}
+
 func TestPath_Merge(t *testing.T) {
 	tests := []struct {
 		path     string