Add get screen resolution code

shell_test.go

@@ -0,0 +1,36 @@
+package adb
+
+import "testing"
+
+func Test_parseScreenResolution(t *testing.T) {
+	type args struct {
+		in string
+	}
+	tests := []struct {
+		name       string
+		args       args
+		wantWidth  int
+		wantLength int
+		wantErr    bool
+	}{
+		{name: "Pixel 4XL", args: args{in: "Physical size: 1440x3040"}, wantWidth: 1440, wantLength: 3040, wantErr: false},
+		{name: "Pixel XL", args: args{in: "Physical size: 1440x2560"}, wantWidth: 1440, wantLength: 2560, wantErr: false},
+		{name: "garbage", args: args{in: "asdfhjkla"}, wantWidth: -1, wantLength: -1, wantErr: true},
+		// TODO: Add test cases.
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w, l, err := parseScreenResolution(tt.args.in)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("parseScreenResolution() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if w != tt.wantWidth {
+				t.Errorf("parseScreenResolution() got = %v, want %v", w, tt.wantWidth)
+			}
+			if l != tt.wantLength {
+				t.Errorf("parseScreenResolution() got1 = %v, want %v", l, tt.wantLength)
+			}
+		})
+	}
+}