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
use itertools::Itertools;
use serde_yaml::Value;
use std::path::Path;
use super::DataResolverError;
pub fn take_sub_value_at_address(
value: &mut Value,
address: &[&str],
) -> Result<Value, DataResolverError> {
use itertools::FoldWhile::{Continue, Done};
return address
.iter()
.fold_while(Ok(value), |acc, i| match acc.unwrap().get_mut(i) {
Some(v) => Continue(Ok(v)),
_ => Done(Err(DataResolverError::KeyNotFound(i.to_string()))),
})
.into_inner()
.map(|v| std::mem::replace(v, Value::Null));
}
pub fn value_from_file(path: &Path) -> Result<Value, DataResolverError> {
let file = std::fs::File::open(&path)?;
let value = serde_yaml::from_reader::<_, Value>(file)?;
Ok(value)
}
pub trait Merge {
fn merge(&mut self, mergee: Self) -> Result<&mut Self, DataResolverError>;
fn merge_at(&mut self, key: &str, mergee: Self) -> Result<&mut Self, DataResolverError>;
}
macro_rules! merge_compat_err {
($self:expr, $mergee:expr) => {
Err(DataResolverError::IncompatibleYamlMerge {
dst: $self.clone(),
src: $mergee,
})
};
}
impl Merge for serde_yaml::Value {
fn merge(&mut self, mut mergee: Self) -> Result<&mut Self, DataResolverError> {
use serde_yaml::Value::{Bool, Mapping, Null, Number, Sequence, String};
if let Null = mergee {
return Ok(self);
}
match self {
Null => {
*self = mergee;
}
Bool(_) => {
if !mergee.is_bool() {
return merge_compat_err! {self, mergee};
}
*self = mergee;
}
Number(_) => {
if !mergee.is_number() {
return merge_compat_err! {self, mergee};
}
*self = mergee;
}
String(_) => {
if !mergee.is_string() {
return merge_compat_err! {self, mergee};
}
*self = mergee;
}
Sequence(list) => {
if let Sequence(ref mut appendee) = mergee {
list.append(appendee);
} else {
return merge_compat_err! {self, mergee};
}
}
Mapping(mapping) => {
if let Mapping(superimposee) = mergee {
for (key, src) in superimposee {
if let Some(dst) = mapping.get_mut(&key) {
dst.merge(src)?;
} else {
mapping.insert(key, src);
}
}
} else {
return merge_compat_err! {self, mergee};
}
}
};
Ok(self)
}
fn merge_at(&mut self, key: &str, mergee: Self) -> Result<&mut Self, DataResolverError> {
match self {
Self::Mapping(mapping) => {
let key: Self = key.into();
match mapping.get_mut(&key) {
Some(value) => {
value.merge(mergee)?;
}
None => {
mapping.insert(key, mergee);
}
}
Ok(self)
}
Self::Null => {
let mut mapping = serde_yaml::Mapping::new();
mapping.insert(key.into(), mergee);
*self = Self::Mapping(mapping);
Ok(self)
}
_ => Err(DataResolverError::CannotMergeIntoNonMapping(self.clone())),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use color_eyre::Result;
use indoc::indoc;
use test_files::TestFiles;
use test_utils::yaml;
#[test]
fn gets_value_from_file() -> Result<()> {
let filename = "index.yml";
let content = indoc! {"
---
ok: true
go: home
"};
let mocks = TestFiles::new();
mocks.file(filename, content);
let file_path = mocks.path().join(filename);
let read_value = value_from_file(&file_path)?;
assert_eq!(serde_yaml::to_string(&read_value)?, content);
Ok(())
}
#[test]
fn takes_sub_value_at_address() -> Result<()> {
let mut value = yaml! {"
---
my:
yaml:
is:
- hella
- deep
"};
let taken = take_sub_value_at_address(&mut value, &["my", "yaml"])?;
assert_eq!(
taken,
yaml! {"
---
is:
- hella
- deep
"}
);
assert_eq!(
value,
yaml! {"
---
my:
yaml:
"}
);
Ok(())
}
}