fix(schema-builder): drop dependent indices and constraints for removed columns. - #12762

Description

The newly added dropIndicesAndConstraintsForRemovedColumns() block is not indented like other
class methods, creating inconsistent style and likely failing formatting/lint expectations for this
file.

Code

src/schema-builder/RdbmsSchemaBuilder.ts[R250-253]

+/**
+ * Drops indices, checks, and unique constraints that involve columns about to be dropped.
+ */
+protected async dropIndicesAndConstraintsForRemovedColumns(): Promise<void> {

Evidence

PR Compliance ID 4 requires avoiding inconsistent style. The new method and its comment begin at
column 0 while surrounding class methods are indented, demonstrating inconsistent formatting in the
changed code.

Rule 4: Remove AI-generated noise
src/schema-builder/RdbmsSchemaBuilder.ts[250-258]
src/schema-builder/RdbmsSchemaBuilder.ts[308-310]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

## Issue description
`dropIndicesAndConstraintsForRemovedColumns()` (and its JSDoc) is not indented consistently with the rest of `RdbmsSchemaBuilder` methods, making the style inconsistent and potentially breaking formatting/lint checks.

## Issue Context
In `src/schema-builder/RdbmsSchemaBuilder.ts`, other methods inside `export class RdbmsSchemaBuilder` are indented (e.g., `private getTablePath`). The new method starts at column 0.

## Fix Focus Areas
- src/schema-builder/RdbmsSchemaBuilder.ts[250-308]

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Description

dropIndicesAndConstraintsForRemovedColumns() calls check.expression.includes(colName) even though
TableCheck.expression is optional, which can throw at runtime during schema sync. Substring matching
can also misidentify constraints (e.g., dropped column "id" matching "order_id"), causing unrelated
CHECK constraints to be dropped or required ones to be missed so dropRemovedColumns() still fails.

Code

src/schema-builder/RdbmsSchemaBuilder.ts[R296-299]

+            const checksToDrop = table.checks.filter((check) =>
+                droppedColumnNames.some((colName) => check.expression.includes(colName))
+            )
+            if (checksToDrop.length > 0) {

Evidence

The PR introduces CHECK selection using check.expression.includes(...) without null-guarding;
TableCheck.expression is defined as optional, so this can throw. Additionally, at least Postgres
populates TableCheck.columnNames, which provides a safer way to detect referenced columns than
substring matching.

src/schema-builder/RdbmsSchemaBuilder.ts[250-307]
src/schema-builder/table/TableCheck.ts[14-37]
src/driver/postgres/PostgresQueryRunner.ts[4218-4231]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

### Issue description
`dropIndicesAndConstraintsForRemovedColumns()` determines which CHECK constraints reference soon-to-be-dropped columns by using `check.expression.includes(colName)`. This is unsafe because `TableCheck.expression` is optional (can be `undefined`, causing a crash), and it is logically incorrect because substring matching is not SQL-identifier aware (false positives/negatives).

### Issue Context
Several drivers (e.g., Postgres) already populate `TableCheck.columnNames`, which is a structured way to know which columns a CHECK constraint references.

### Fix Focus Areas
- src/schema-builder/RdbmsSchemaBuilder.ts[292-305]
- src/schema-builder/table/TableCheck.ts[14-37]
- src/driver/postgres/PostgresQueryRunner.ts[4218-4231]

### Suggested fix
1) Prefer structured matching:
- If `check.columnNames?.length`, drop when `check.columnNames` intersects `droppedColumnNames`.
2) Only if `columnNames` is unavailable, fall back to expression-based detection, but:
- Guard `check.expression` (skip or treat as non-match when missing)
- Use a safer identifier match (e.g., word-boundary/quoted-identifier aware regex) rather than plain substring.

This prevents crashes and avoids dropping unrelated CHECK constraints while still reliably removing those that block column drops.

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Description

The PR adds logic to drop unique and check constraints for soon-to-be-removed columns, but there is
no corresponding functional test coverage for these new cases, increasing regression risk.

Code

src/schema-builder/RdbmsSchemaBuilder.ts[R282-289]

+        const uniquesToDrop = table.uniques.filter((unique) =>
+            unique.columnNames.some((colName) => droppedColumnNames.includes(colName))
+        )
+        if (uniquesToDrop.length > 0) {
+            this.dataSource.logger.logSchemaBuild(
+                `dropping unique constraints from table "${table.name}" because they reference dropped columns`,
+            )
+            await this.queryRunner.dropUniqueConstraints(table, uniquesToDrop)

Evidence

PR Compliance ID 3 expects issue fixes to live in the functional test suite. The diff adds new
behavior for dropping unique/check constraints, while the existing related functional test asserts
only index removal when dropping a column and does not cover unique/check constraints.

Rule 3: Prefer functional tests over per-issue tests
src/schema-builder/RdbmsSchemaBuilder.ts[282-305]
test/functional/schema-builder/column/drop/drop-column-with-index/drop-column-with-index.test.ts[23-47]

Agent prompt

The issue below was found during a code review. Follow the provided context and guidance below and implement a solution

## Issue description
New schema sync behavior drops unique and check constraints referencing removed columns, but existing functional tests only cover dropping an index when dropping a column.

## Issue Context
`dropIndicesAndConstraintsForRemovedColumns()` now includes dropping `table.uniques` and `table.checks` when they reference columns being removed. There is an existing functional test for dropping a column with an index, but it does not assert unique/check constraint behavior.

## Fix Focus Areas
- src/schema-builder/RdbmsSchemaBuilder.ts[272-305]
- test/functional/schema-builder/column/drop/drop-column-with-index/drop-column-with-index.test.ts[23-47]

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