1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191

use serde;
use std;

use Revision;

/// Builder for constructing a change item.
#[derive(Debug)]
pub struct ChangeItemBuilder {
    target: ChangeItem,
}

impl ChangeItemBuilder {
    /// Constructs a new change item builder.
    ///
    /// The change item contained within the builder has the given revision.
    ///
    pub fn new(rev: Revision) -> Self {
        ChangeItemBuilder {
            target: ChangeItem {
                rev: rev,
                _dummy: std::marker::PhantomData,
            },
        }
    }

    /// Constructs a new change item builder.
    ///
    /// The change item contained within the builder is assigned a revision
    /// equivalent to the given revision string.
    ///
    /// # Panics
    ///
    /// Panics if the revision string is invalid.
    ///
    pub fn new_from_rev_str<R: AsRef<str>>(rev: R) -> Self {
        ChangeItemBuilder {
            target: ChangeItem {
                rev: Revision::parse(rev.as_ref())
                         .expect("Cannot build ChangeItem from invalid revision string"),
                _dummy: std::marker::PhantomData,
            },
        }
    }

    /// Returns the change item contained within the builder.
    pub fn unwrap(self) -> ChangeItem {
        self.target
    }
}

/// Document leaf as returned in a change result.
#[derive(Clone, Debug, PartialEq)]
pub struct ChangeItem {
    /// Revision of the document leaf.
    pub rev: Revision,

    _dummy: std::marker::PhantomData<()>,
}

impl ChangeItem {
    #[doc(hidden)]
    pub fn new(rev: Revision) -> Self {
        ChangeItem {
            rev: rev,
            _dummy: std::marker::PhantomData,
        }
    }
}

impl serde::Deserialize for ChangeItem {
    fn deserialize<D>(d: &mut D) -> Result<Self, D::Error>
        where D: serde::Deserializer
    {
        enum Field {
            Rev,
        }

        impl serde::Deserialize for Field {
            fn deserialize<D>(d: &mut D) -> Result<Field, D::Error>
                where D: serde::Deserializer
            {
                struct Visitor;

                impl serde::de::Visitor for Visitor {
                    type Value = Field;

                    fn visit_str<E>(&mut self, value: &str) -> Result<Field, E>
                        where E: serde::de::Error
                    {
                        match value {
                            "rev" => Ok(Field::Rev),
                            _ => Err(E::unknown_field(value)),
                        }
                    }
                }

                d.visit(Visitor)
            }
        }

        struct Visitor;

        impl serde::de::Visitor for Visitor {
            type Value = ChangeItem;

            fn visit_map<V>(&mut self, mut visitor: V) -> Result<Self::Value, V::Error>
                where V: serde::de::MapVisitor
            {
                let mut rev = None;
                loop {
                    match try!(visitor.visit_key()) {
                        Some(Field::Rev) => {
                            rev = Some(try!(visitor.visit_value()));
                        }
                        None => {
                            break;
                        }
                    }
                }

                try!(visitor.end());

                let rev = match rev {
                    Some(x) => x,
                    None => try!(visitor.missing_field("rev")),
                };

                Ok(ChangeItem {
                    rev: rev,
                    _dummy: std::marker::PhantomData,
                })
            }
        }

        static FIELDS: &'static [&'static str] = &["rev"];
        d.visit_struct("ChangeItem", FIELDS, Visitor)
    }
}

#[cfg(test)]
mod tests {

    use serde_json;
    use std;

    use Revision;
    use super::ChangeItem;
    use super::ChangeItemBuilder;

    #[test]
    fn builder_new() {
        let expected = ChangeItem {
            rev: Revision::parse("42-1234567890abcdef1234567890abcdef").unwrap(),
            _dummy: std::marker::PhantomData,
        };
        let rev = Revision::parse("42-1234567890abcdef1234567890abcdef").unwrap();
        let got = ChangeItemBuilder::new(rev).unwrap();
        assert_eq!(expected, got);
    }

    #[test]
    fn builder_new_from_rev_str() {
        let expected = ChangeItem {
            rev: Revision::parse("42-1234567890abcdef1234567890abcdef").unwrap(),
            _dummy: std::marker::PhantomData,
        };
        let rev = "42-1234567890abcdef1234567890abcdef";
        let got = ChangeItemBuilder::new_from_rev_str(rev).unwrap();
        assert_eq!(expected, got);
    }

    #[test]
    fn deserialization_ok_with_all_fields() {
        let rev = "42-1234567890abcdef1234567890abcdef";
        let expected = ChangeItemBuilder::new_from_rev_str(rev).unwrap();
        let source = serde_json::builder::ObjectBuilder::new()
                         .insert("rev", rev)
                         .unwrap();
        let s = serde_json::to_string(&source).unwrap();
        let got = serde_json::from_str(&s).unwrap();
        assert_eq!(expected, got);
    }

    #[test]
    fn deserialization_nok_with_no_rev_field() {
        let source = serde_json::builder::ObjectBuilder::new().unwrap();
        let s = serde_json::to_string(&source).unwrap();
        let got = serde_json::from_str::<ChangeItem>(&s);
        expect_json_error_missing_field!(got, "rev");
    }
}