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squawk_linter/
analyze.rs

1use squawk_syntax::ast;
2
3fn has_foreign_key_constraint(create_table: &ast::CreateTable) -> bool {
4    if let Some(table_arg_list) = create_table.table_arg_list() {
5        for arg in table_arg_list.args() {
6            match arg {
7                ast::TableArg::TableConstraint(ast::TableConstraint::ForeignKeyConstraint(_)) => {
8                    return true;
9                }
10                ast::TableArg::Column(column) => {
11                    if let Some(ast::ColumnConstraint::ReferencesConstraint(_)) =
12                        column.constraint()
13                    {
14                        return true;
15                    }
16                }
17                _ => {}
18            }
19        }
20    }
21    false
22}
23
24/// Returns `true` if the statement might impede normal database queries.
25pub fn possibly_slow_stmt(stmt: &ast::Stmt) -> bool {
26    // We assume all DDL like Alter, Create, Drop could affect queries.
27    //
28    // We don't want to warn about DML style queries, like select,
29    // insert, update, delete, etc. This allows using squawk for normal SQL
30    // editing.
31    match stmt {
32        // Without a foreign key constraint, creating a new table should be fast
33        ast::Stmt::CreateTable(create_table) => has_foreign_key_constraint(create_table),
34        | ast::Stmt::AlterAggregate(_)
35        | ast::Stmt::AlterCollation(_)
36        | ast::Stmt::AlterConversion(_)
37        | ast::Stmt::AlterDatabase(_)
38        | ast::Stmt::AlterDefaultPrivileges(_)
39        | ast::Stmt::AlterDomain(_)
40        | ast::Stmt::AlterEventTrigger(_)
41        | ast::Stmt::AlterExtension(_)
42        | ast::Stmt::AlterForeignDataWrapper(_)
43        | ast::Stmt::AlterForeignTable(_)
44        | ast::Stmt::AlterFunction(_)
45        | ast::Stmt::AlterGroup(_)
46        | ast::Stmt::AlterIndex(_)
47        | ast::Stmt::AlterLanguage(_)
48        | ast::Stmt::AlterLargeObject(_)
49        | ast::Stmt::AlterMaterializedView(_)
50        | ast::Stmt::AlterOperator(_)
51        | ast::Stmt::AlterOperatorClass(_)
52        | ast::Stmt::AlterOperatorFamily(_)
53        | ast::Stmt::AlterPolicy(_)
54        | ast::Stmt::AlterProcedure(_)
55        | ast::Stmt::AlterPublication(_)
56        | ast::Stmt::AlterRole(_)
57        | ast::Stmt::AlterRoutine(_)
58        | ast::Stmt::AlterRule(_)
59        | ast::Stmt::AlterSchema(_)
60        | ast::Stmt::AlterSequence(_)
61        | ast::Stmt::AlterServer(_)
62        | ast::Stmt::AlterStatistics(_)
63        | ast::Stmt::AlterSubscription(_)
64        | ast::Stmt::AlterSystem(_)
65        | ast::Stmt::AlterTable(_)
66        | ast::Stmt::AlterTablespace(_)
67        | ast::Stmt::AlterTextSearchConfiguration(_)
68        | ast::Stmt::AlterTextSearchDictionary(_)
69        | ast::Stmt::AlterTextSearchParser(_)
70        | ast::Stmt::AlterTextSearchTemplate(_)
71        | ast::Stmt::AlterTrigger(_)
72        | ast::Stmt::AlterType(_)
73        | ast::Stmt::AlterUser(_)
74        | ast::Stmt::AlterUserMapping(_)
75        | ast::Stmt::AlterView(_)
76        | ast::Stmt::CreateAccessMethod(_)
77        | ast::Stmt::CreateAggregate(_)
78        | ast::Stmt::CreateCast(_)
79        | ast::Stmt::CreateCollation(_)
80        | ast::Stmt::CreateConversion(_)
81        | ast::Stmt::CreateDatabase(_)
82        | ast::Stmt::CreateDomain(_)
83        | ast::Stmt::CreateEventTrigger(_)
84        | ast::Stmt::CreateExtension(_)
85        | ast::Stmt::CreateForeignDataWrapper(_)
86        | ast::Stmt::CreateForeignTable(_)
87        | ast::Stmt::CreateFunction(_)
88        | ast::Stmt::CreateGroup(_)
89        | ast::Stmt::CreateIndex(_)
90        | ast::Stmt::CreateLanguage(_)
91        | ast::Stmt::CreateMaterializedView(_)
92        | ast::Stmt::CreateOperator(_)
93        | ast::Stmt::CreateOperatorClass(_)
94        | ast::Stmt::CreateOperatorFamily(_)
95        | ast::Stmt::CreatePolicy(_)
96        | ast::Stmt::CreateProcedure(_)
97        | ast::Stmt::CreatePublication(_)
98        | ast::Stmt::CreateRole(_)
99        | ast::Stmt::CreateRule(_)
100        | ast::Stmt::CreateSchema(_)
101        | ast::Stmt::CreateSequence(_)
102        | ast::Stmt::CreateServer(_)
103        | ast::Stmt::CreateStatistics(_)
104        | ast::Stmt::CreateSubscription(_)
105        | ast::Stmt::CreateTableAs(_)
106        | ast::Stmt::CreateTablespace(_)
107        | ast::Stmt::CreateTextSearchConfiguration(_)
108        | ast::Stmt::CreateTextSearchDictionary(_)
109        | ast::Stmt::CreateTextSearchParser(_)
110        | ast::Stmt::CreateTextSearchTemplate(_)
111        | ast::Stmt::CreateTransform(_)
112        | ast::Stmt::CreateTrigger(_)
113        | ast::Stmt::CreateType(_)
114        | ast::Stmt::CreateUser(_)
115        | ast::Stmt::CreateUserMapping(_)
116        | ast::Stmt::CreateView(_)
117        | ast::Stmt::DropAccessMethod(_)
118        | ast::Stmt::DropAggregate(_)
119        | ast::Stmt::DropCast(_)
120        | ast::Stmt::DropCollation(_)
121        | ast::Stmt::DropConversion(_)
122        | ast::Stmt::DropDatabase(_)
123        | ast::Stmt::DropDomain(_)
124        | ast::Stmt::DropEventTrigger(_)
125        | ast::Stmt::DropExtension(_)
126        | ast::Stmt::DropForeignDataWrapper(_)
127        | ast::Stmt::DropForeignTable(_)
128        | ast::Stmt::DropFunction(_)
129        | ast::Stmt::DropGroup(_)
130        | ast::Stmt::DropIndex(_)
131        | ast::Stmt::DropLanguage(_)
132        | ast::Stmt::DropMaterializedView(_)
133        | ast::Stmt::DropOperator(_)
134        | ast::Stmt::DropOperatorClass(_)
135        | ast::Stmt::DropOperatorFamily(_)
136        | ast::Stmt::DropOwned(_)
137        | ast::Stmt::DropPolicy(_)
138        | ast::Stmt::DropProcedure(_)
139        | ast::Stmt::DropPublication(_)
140        | ast::Stmt::DropRole(_)
141        | ast::Stmt::DropRoutine(_)
142        | ast::Stmt::DropRule(_)
143        | ast::Stmt::DropSchema(_)
144        | ast::Stmt::DropSequence(_)
145        | ast::Stmt::DropServer(_)
146        | ast::Stmt::DropStatistics(_)
147        | ast::Stmt::DropSubscription(_)
148        | ast::Stmt::DropTable(_)
149        | ast::Stmt::DropTablespace(_)
150        | ast::Stmt::DropTextSearchConfig(_)
151        | ast::Stmt::DropTextSearchDict(_)
152        | ast::Stmt::DropTextSearchParser(_)
153        | ast::Stmt::DropTextSearchTemplate(_)
154        | ast::Stmt::DropTransform(_)
155        | ast::Stmt::DropTrigger(_)
156        | ast::Stmt::DropType(_)
157        | ast::Stmt::DropUser(_)
158        | ast::Stmt::DropUserMapping(_)
159        | ast::Stmt::DropView(_)
160        // non-Alter, Create, Drop statements
161        | ast::Stmt::Cluster(_)
162        | ast::Stmt::CommentOn(_)
163        | ast::Stmt::ImportForeignSchema(_)
164        | ast::Stmt::Load(_)
165        | ast::Stmt::Lock(_)
166        | ast::Stmt::Refresh(_)
167        | ast::Stmt::Reindex(_)
168        | ast::Stmt::Truncate(_)
169        | ast::Stmt::Vacuum(_)
170        => true,
171        ast::Stmt::Analyze(_)
172        | ast::Stmt::Begin(_)
173        | ast::Stmt::Call(_)
174        | ast::Stmt::Checkpoint(_)
175        | ast::Stmt::Close(_)
176        | ast::Stmt::Commit(_)
177        | ast::Stmt::Copy(_)
178        | ast::Stmt::Deallocate(_)
179        | ast::Stmt::Declare(_)
180        | ast::Stmt::Delete(_)
181        | ast::Stmt::Discard(_)
182        | ast::Stmt::Do(_)
183        | ast::Stmt::Execute(_)
184        | ast::Stmt::Explain(_)
185        | ast::Stmt::Fetch(_)
186        | ast::Stmt::Grant(_)
187        | ast::Stmt::Insert(_)
188        | ast::Stmt::Listen(_)
189        | ast::Stmt::Merge(_)
190        | ast::Stmt::Move(_)
191        | ast::Stmt::Notify(_)
192        | ast::Stmt::ParenSelect(_)
193        | ast::Stmt::Prepare(_)
194        | ast::Stmt::PrepareTransaction(_)
195        | ast::Stmt::Reassign(_)
196        | ast::Stmt::ReleaseSavepoint(_)
197        | ast::Stmt::Reset(_)
198        | ast::Stmt::Revoke(_)
199        | ast::Stmt::Rollback(_)
200        | ast::Stmt::Savepoint(_)
201        | ast::Stmt::SecurityLabel(_)
202        | ast::Stmt::Select(_)
203        | ast::Stmt::SelectInto(_)
204        | ast::Stmt::Set(_)
205        | ast::Stmt::SetConstraints(_)
206        | ast::Stmt::SetRole(_)
207        | ast::Stmt::SetSessionAuth(_)
208        | ast::Stmt::ResetSessionAuth(_)
209        | ast::Stmt::SetTransaction(_)
210        | ast::Stmt::Show(_)
211        | ast::Stmt::Table(_)
212        | ast::Stmt::Unlisten(_)
213        | ast::Stmt::Update(_)
214        | ast::Stmt::Values(_) => false,
215    }
216}
217
218#[cfg(test)]
219mod tests {
220    use super::*;
221    use squawk_syntax::SourceFile;
222
223    #[test]
224    fn alter_table() {
225        let sql = "ALTER TABLE users ADD COLUMN email TEXT;";
226        let file = SourceFile::parse(sql);
227        let stmts = file.tree().stmts().next().unwrap();
228        assert!(possibly_slow_stmt(&stmts));
229    }
230
231    #[test]
232    fn select() {
233        let sql = "select 1;";
234        let file = SourceFile::parse(sql);
235        let stmts = file.tree().stmts().next().unwrap();
236        assert!(!possibly_slow_stmt(&stmts));
237    }
238
239    #[test]
240    fn create_table_without_foreign_key() {
241        let sql = "create table foo (id integer generated by default as identity primary key);";
242        let file = SourceFile::parse(sql);
243        let stmts = file.tree().stmts().next().unwrap();
244        assert!(!possibly_slow_stmt(&stmts));
245    }
246
247    #[test]
248    fn create_table_with_foreign_key() {
249        let sql = "create table foo (id integer, user_id integer references users(id));";
250        let file = SourceFile::parse(sql);
251        let stmts = file.tree().stmts().next().unwrap();
252        assert!(possibly_slow_stmt(&stmts));
253    }
254
255    #[test]
256    fn create_table_with_table_level_foreign_key() {
257        let sql = "create table foo (id integer, user_id integer, foreign key (user_id) references users(id));";
258        let file = SourceFile::parse(sql);
259        let stmts = file.tree().stmts().next().unwrap();
260        assert!(possibly_slow_stmt(&stmts));
261    }
262}