pgevolve-core 0.3.5

Postgres declarative schema management — core library (parser, IR, diff, planner) powering the pgevolve CLI.
Documentation 
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

//! `compression-change-not-retroactive` lint rule.
//!
//! Warns on any SET COMPRESSION change. Existing `TOASTed` values keep
//! their original codec; only new/updated rows get the new codec.

use crate::diff::change::Change;
use crate::diff::changeset::ChangeSet;
use crate::diff::table_op::TableOp;
use crate::lint::finding::{Finding, Severity};

/// Rule ID emitted on the finding; matches the file name.
pub const RULE_ID: &str = "compression-change-not-retroactive";

pub fn check(cs: &ChangeSet) -> Vec<Finding> {
    let mut findings = Vec::new();
    for entry in cs.iter() {
        let Change::AlterTable { qname, ops } = &entry.change else {
            continue;
        };
        for op_entry in ops {
            let TableOp::SetColumnCompression { name, .. } = &op_entry.op else {
                continue;
            };
            findings.push(Finding {
                severity: Severity::Warning,
                rule: RULE_ID,
                message: format!(
                    "column {qname}.{name} compression change is not retroactive; \
                     existing TOASTed values keep their original codec \
                     until rewritten by UPDATE or VACUUM FULL",
                ),
                location: None,
            });
        }
    }
    findings
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::diff::changeset::ChangeSet;
    use crate::diff::destructiveness::Destructiveness;
    use crate::diff::table_op::TableOpEntry;
    use crate::identifier::{Identifier, QualifiedName};
    use crate::ir::column::Compression;

    fn id(s: &str) -> Identifier {
        Identifier::from_unquoted(s).unwrap()
    }

    fn qn(schema: &str, name: &str) -> QualifiedName {
        QualifiedName::new(id(schema), id(name))
    }

    fn changeset_with_compression_change(compression: Option<Compression>) -> ChangeSet {
        let mut cs = ChangeSet::new();
        cs.push(
            Change::AlterTable {
                qname: qn("app", "t"),
                ops: vec![TableOpEntry {
                    op: TableOp::SetColumnCompression {
                        name: id("blob"),
                        compression,
                    },
                    destructiveness: Destructiveness::Safe,
                }],
            },
            Destructiveness::Safe,
        );
        cs
    }

    #[test]
    fn any_compression_change_fires() {
        // Pglz → Lz4 (represented as SetColumnCompression { compression: Some(Lz4) }).
        let cs = changeset_with_compression_change(Some(Compression::Lz4));
        let findings = check(&cs);
        assert_eq!(findings.len(), 1, "expected one finding: {findings:?}");
        assert_eq!(findings[0].rule, RULE_ID);
        assert_eq!(findings[0].severity, Severity::Warning);
    }

    #[test]
    fn set_to_default_also_fires() {
        // Lz4 → None (cluster default) still emits a finding.
        let cs = changeset_with_compression_change(None);
        let findings = check(&cs);
        assert_eq!(findings.len(), 1, "expected one finding: {findings:?}");
        assert_eq!(findings[0].rule, RULE_ID);
        assert_eq!(findings[0].severity, Severity::Warning);
    }

    #[test]
    fn no_change_no_finding() {
        let cs = ChangeSet::new();
        let findings = check(&cs);
        assert!(
            findings.is_empty(),
            "empty changeset must yield no findings"
        );
    }

    #[test]
    fn multiple_columns_each_fires() {
        // Two compression ops in one AlterTable → two findings.
        let mut cs = ChangeSet::new();
        cs.push(
            Change::AlterTable {
                qname: qn("app", "t"),
                ops: vec![
                    TableOpEntry {
                        op: TableOp::SetColumnCompression {
                            name: id("blob"),
                            compression: Some(Compression::Lz4),
                        },
                        destructiveness: Destructiveness::Safe,
                    },
                    TableOpEntry {
                        op: TableOp::SetColumnCompression {
                            name: id("data"),
                            compression: Some(Compression::Pglz),
                        },
                        destructiveness: Destructiveness::Safe,
                    },
                ],
            },
            Destructiveness::Safe,
        );
        let findings = check(&cs);
        assert_eq!(findings.len(), 2, "expected two findings: {findings:?}");
    }
}