diesel/pg/types/
json.rs

1//! Support for JSON and `jsonb` values under PostgreSQL.
2
3extern crate serde_json;
4
5use std::io::prelude::*;
6
7use deserialize::{self, FromSql};
8use pg::Pg;
9use serialize::{self, IsNull, Output, ToSql};
10use sql_types;
11
12#[allow(dead_code)]
13mod foreign_derives {
14    use super::serde_json;
15    use sql_types::{Json, Jsonb};
16
17    #[derive(FromSqlRow, AsExpression)]
18    #[diesel(foreign_derive)]
19    #[sql_type = "Json"]
20    #[sql_type = "Jsonb"]
21    struct SerdeJsonValueProxy(serde_json::Value);
22}
23
24impl FromSql<sql_types::Json, Pg> for serde_json::Value {
25    fn from_sql(bytes: Option<&[u8]>) -> deserialize::Result<Self> {
26        let bytes = not_none!(bytes);
27        serde_json::from_slice(bytes).map_err(|_| "Invalid Json".into())
28    }
29}
30
31impl ToSql<sql_types::Json, Pg> for serde_json::Value {
32    fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
33        serde_json::to_writer(out, self)
34            .map(|_| IsNull::No)
35            .map_err(Into::into)
36    }
37}
38
39impl FromSql<sql_types::Jsonb, Pg> for serde_json::Value {
40    fn from_sql(bytes: Option<&[u8]>) -> deserialize::Result<Self> {
41        let bytes = not_none!(bytes);
42        if bytes[0] != 1 {
43            return Err("Unsupported JSONB encoding version".into());
44        }
45        serde_json::from_slice(&bytes[1..]).map_err(|_| "Invalid Json".into())
46    }
47}
48
49impl ToSql<sql_types::Jsonb, Pg> for serde_json::Value {
50    fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
51        out.write_all(&[1])?;
52        serde_json::to_writer(out, self)
53            .map(|_| IsNull::No)
54            .map_err(Into::into)
55    }
56}
57
58#[test]
59fn json_to_sql() {
60    let mut bytes = Output::test();
61    let test_json = serde_json::Value::Bool(true);
62    ToSql::<sql_types::Json, Pg>::to_sql(&test_json, &mut bytes).unwrap();
63    assert_eq!(bytes, b"true");
64}
65
66#[test]
67fn some_json_from_sql() {
68    let input_json = b"true";
69    let output_json: serde_json::Value =
70        FromSql::<sql_types::Json, Pg>::from_sql(Some(input_json)).unwrap();
71    assert_eq!(output_json, serde_json::Value::Bool(true));
72}
73
74#[test]
75fn bad_json_from_sql() {
76    let uuid: Result<serde_json::Value, _> =
77        FromSql::<sql_types::Json, Pg>::from_sql(Some(b"boom"));
78    assert_eq!(uuid.unwrap_err().to_string(), "Invalid Json");
79}
80
81#[test]
82fn no_json_from_sql() {
83    let uuid: Result<serde_json::Value, _> = FromSql::<sql_types::Json, Pg>::from_sql(None);
84    assert_eq!(
85        uuid.unwrap_err().to_string(),
86        "Unexpected null for non-null column"
87    );
88}
89
90#[test]
91fn jsonb_to_sql() {
92    let mut bytes = Output::test();
93    let test_json = serde_json::Value::Bool(true);
94    ToSql::<sql_types::Jsonb, Pg>::to_sql(&test_json, &mut bytes).unwrap();
95    assert_eq!(bytes, b"\x01true");
96}
97
98#[test]
99fn some_jsonb_from_sql() {
100    let input_json = b"\x01true";
101    let output_json: serde_json::Value =
102        FromSql::<sql_types::Jsonb, Pg>::from_sql(Some(input_json)).unwrap();
103    assert_eq!(output_json, serde_json::Value::Bool(true));
104}
105
106#[test]
107fn bad_jsonb_from_sql() {
108    let uuid: Result<serde_json::Value, _> =
109        FromSql::<sql_types::Jsonb, Pg>::from_sql(Some(b"\x01boom"));
110    assert_eq!(uuid.unwrap_err().to_string(), "Invalid Json");
111}
112
113#[test]
114fn bad_jsonb_version_from_sql() {
115    let uuid: Result<serde_json::Value, _> =
116        FromSql::<sql_types::Jsonb, Pg>::from_sql(Some(b"\x02true"));
117    assert_eq!(
118        uuid.unwrap_err().to_string(),
119        "Unsupported JSONB encoding version"
120    );
121}
122
123#[test]
124fn no_jsonb_from_sql() {
125    let uuid: Result<serde_json::Value, _> = FromSql::<sql_types::Jsonb, Pg>::from_sql(None);
126    assert_eq!(
127        uuid.unwrap_err().to_string(),
128        "Unexpected null for non-null column"
129    );
130}
diesel/pg/types/json.rs

diesel/pg/types/
json.rs
