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

use std::collections::btree_map::Entry;
use std::collections::BTreeMap;

use lcov::Report;

use lcov::report::MergeError;

use lcov::report::section::branch::Value as BranchValue;
use lcov::report::section::function::Value as FunctionValue;
use lcov::report::section::line::Value as LineValue;
use lcov::report::section::Value as SectionValue;

pub fn diff_reports(first: &Report, second: &Report) -> Result<Report, MergeError> {
    let mut rep = Report::new();
    rep.merge(first.to_owned())?;
    rep.diff(second)?;
    Ok(rep)
}

pub trait Diff {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError>;
}

impl Diff for Report {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        self.sections.diff(&other.sections)
    }
}

impl Diff for BranchValue {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        if let BranchValue { taken: Some(taken) } = *other {
            // We don't care about exact count. It's only important is the branch covered or not
            if taken > 0 {
                self.taken = None;
            }
        };
        Ok(())
    }
}

impl Diff for SectionValue {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        self.functions.diff(&other.functions)?;
        self.branches.diff(&other.branches)?;
        self.lines.diff(&other.lines)?;
        Ok(())
    }
}

impl Diff for FunctionValue {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        if let Some(start_line) = other.start_line.as_ref() {
            if let Some(my_start_line) = self.start_line.as_ref() {
                if start_line != my_start_line {
                    return Err(MergeError::UnmatchedFunctionLine);
                }
            }
        }
        // As for branch it's only important if it covered or not
        if other.count > 0 {
            self.count = 0;
        }
        Ok(())
    }
}

impl Diff for LineValue {
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        if let Some(checksum) = other.checksum.as_ref() {
            if let Some(my_checksum) = self.checksum.as_ref() {
                if checksum != my_checksum {
                    return Err(MergeError::UnmatchedChecksum);
                }
            }
        }
        // As for branch it's only important if it covered or not
        if other.count > 0 {
            self.count = 0;
        }
        Ok(())
    }
}

impl<K, V> Diff for BTreeMap<K, V>
where
    K: Ord + Clone,
    V: Diff,
{
    fn diff(&mut self, other: &Self) -> Result<(), MergeError> {
        for (key, value) in other {
            match self.entry(key.clone()) {
                Entry::Vacant(_) => {}
                Entry::Occupied(mut e) => e.get_mut().diff(value)?,
            }
        }
        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use crate::diff_reports;
    use lcov::report::MergeError;
    use lcov::{Reader, Report};

    #[test]
    fn diff_report() -> Result<(), MergeError> {
        let input = "\
TN:
SF:target.c
FN:1,main
FNDA:1,main
DA:1,1
DA:3,1
DA:4,1
DA:5,1
DA:6,1
DA:7,1
DA:8,0
DA:11,1
DA:12,0
DA:14,1
DA:15,1
DA:17,1
end_of_record
";
        let reader1 = Reader::new(input.as_bytes());
        let report1 = Report::from_reader(reader1).unwrap();

        let input2 = "\
TN:
SF:target.c
FN:1,main
FNDA:1,main
DA:1,1
DA:3,1
DA:4,1
DA:5,1
DA:6,1
DA:7,1
DA:8,1
DA:11,1
DA:12,0
DA:14,1
DA:15,1
DA:17,1
end_of_record
";

        let expected_lcov = "\
TN:
SF:target.c
FN:1,main
FNDA:0,main
FNF:1
FNH:0
DA:1,0
DA:3,0
DA:4,0
DA:5,0
DA:6,0
DA:7,0
DA:8,1
DA:11,0
DA:12,0
DA:14,0
DA:15,0
DA:17,0
LF:12
LH:1
end_of_record
";
        let reader2 = Reader::new(input2.as_bytes());
        let report2 = Report::from_reader(reader2).unwrap();

        let expected_report = Report::from_reader(Reader::new(expected_lcov.as_bytes())).unwrap();

        let diff_rep = diff_reports(&report2, &report1).unwrap();

        for pair in diff_rep.into_records().zip(expected_report.into_records()) {
            assert_eq!(pair.0, pair.1)
        }
        Ok(())
    }
}