fix(db): widen every varchar column to TEXT on PostgreSQL - #448
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A bare `:string` migration column compiles to `varchar(255)` on PostgreSQL but to unconstrained TEXT affinity on SQLite. Because SQLite is the default adapter for development, test, and most self-hosted deployments, a write longer than 255 characters passes locally and fails only on PostgreSQL with ERROR 22001 (string_data_right_truncation). 20260616120000 fixed the six columns that were actively crashing library scans (#286). It hand-listed them, so it left the rest of the class in place, including `subtitles.file_path` (built from the media path plus a language suffix, so strictly longer than the `media_files.path` that forced the original fix), `import_sessions.scan_path`, `transcode_jobs.output_path`, `library_paths.path`, and the unbounded provider error strings in `import_lists.sync_error` and `plex_*.last_auth_error`. A migrated database still carried 218 such columns. Widening removes an unintended constraint rather than relaxing a real one: the schema declares 245 `:string` columns and never once passes `size:`, so no varchar length here was ever chosen deliberately. Limits the application actually intends live in changesets via validate_length/3. The migration introspects information_schema rather than enumerating columns, so it covers every table regardless of migration history and cannot silently miss one. Oban tables are excluded since Oban owns that schema. On SQLite it is a no-op. `varchar(n)` -> `text` is binary-coercible, so PostgreSQL skips the table rewrite and dependent indexes stay valid. `down` is a deliberate no-op. Narrowing hard-fails once a long value is stored, and a self-hosted operator rolling back a release must never hit a migration that refuses to run; a wider column never breaks older code. Two guards keep it from regressing. A source check runs on every adapter so the mistake surfaces locally instead of only in the PostgreSQL CI job, grandfathering migrations at or before this one by timestamp rather than by a drift-prone allowlist. A schema check asserts the migrated database holds no varchar at all. Verified on PostgreSQL: 218 varchar columns before the migration, 0 after. The source guard was confirmed to fail against a decoy migration before being confirmed green. Closes #286
…utoff hole
Addresses code review of the varchar sweep. Three of the findings were real
defects in the first commit, two of them serious.
Array columns were missed by all three mechanisms. `{:array, :string}` compiles
to `varchar(255)[]`, which reports `data_type = 'ARRAY'` in information_schema
rather than `'character varying'`, so neither the migration nor the schema
assertion saw it, and the source regex required `:string` immediately after the
comma. Six such columns existed, and `custom_formats.patterns` is a live bug:
`Mydia.Settings.CustomFormat` explicitly permits 500-character patterns while
the column truncated at 255 on PostgreSQL. Worse, the schema test reported zero
varchar columns while they remained, so its green was actively misleading.
The migration version collided with `20260813140000_widen_byte_size_columns_to_bigint.exs`
on origin/fix/postgres-int4-byte-columns. Ecto raises
`Ecto.MigrationError` on duplicate versions from both `run/4` and `migrations/3`,
and the migrator runs in the supervision tree, so merging both branches would
have failed boot on every install rather than merely failing a mix task.
Renamed to 20260813215500.
The timestamp cutoff had a hole. Ecto selects pending migrations with
`version not in applied_versions`, so a branch cut before the sweep but merged
after it runs *after* the sweep on an already-migrated database while running
*before* it on a fresh CI one. The cutoff grandfathered exactly that file, so the
bug would reach production with CI green. Replaced with an explicit
grandfathered list, matching the convention in no_raw_table_rebuild_test.exs,
plus a staleness check. This is no longer hypothetical: another branch carries
20260813160000, which the cutoff would have exempted after the rename.
Also widened the source regex to the forms that actually produce varchar and
were previously invisible: parenthesised `add(:foo, :string)` (which `mix format`
preserves, since ecto_sql exports add/modify in locals_without_parens), `:varchar`,
`references(..., type: :string)`, `remove` (whose rollback re-adds the column),
and `Helpers.modify_column_type/3`.
Oban and ErrorTracker are now both excluded from the sweep and the assertion.
Previously only Oban was, so the migration rewrote ErrorTracker's dep-owned
column types while the moduledoc claimed such tables were off limits, and a
future ErrorTracker migration adding a varchar column would have failed the
guard with no mydia source to fix.
Verified on PostgreSQL: 219 columns before (213 scalar, 6 array), 0 after, and
custom_formats.patterns is now text[] with no length limit. The guard was
confirmed to fail against four decoys covering the plain, array, parenthesised,
and backdated-timestamp forms. Full precommit: 7706 tests, 0 failures.
…har-columns-postgres
The new guard caught this on the merge with master: `20260813160000` landed while this branch was in review and declares `add :language, :string`, which is `varchar(255)` on PostgreSQL. A language code is short in practice, so this is the rule rather than a live truncation risk. Fixing it at the source instead of grandfathering it keeps the invariant exact, and the migration is unreleased so there is no deployed schema to reconcile. This is also the case the grandfathered list exists to catch. Under the earlier timestamp-cutoff design, 20260813160000 sorts below the sweep at 20260813215500 and would have been exempted silently.
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📝 WalkthroughWalkthroughThe changes standardize application database columns on ChangesVarchar to text migration
Estimated code review effort: 3 (Moderate) | ~20 minutes Mergeability Score: ⚪ Minimal · up to This PR removes unintended PostgreSQL varchar limits across migration-defined columns and adds guards to prevent regressions; no actionable merge-blocking risk remains after normal checks and review. 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches📝 Generate docstrings
🧪 Generate unit tests (beta)
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Inline comments:
In `@test/mydia/repo/migrations/no_varchar_columns_test.exs`:
- Line 112: Update the array declaration regex in the migration test to include
remove alongside add, add_if_not_exists, and modify, matching both formatted
remove forms with the existing whitespace and optional-parenthesis handling.
🪄 Autofix
Fix all unresolved CodeRabbit comments on this PR:
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- Create a new PR with the fixes
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro Plus
Run ID: 583d3ba7-c571-4659-b608-7ebf7fdd13af
📒 Files selected for processing (4)
AGENTS.mdpriv/repo/migrations/20260813160000_create_audio_language_preferences.exspriv/repo/migrations/20260813215500_widen_all_varchar_columns_to_text.exstest/mydia/repo/migrations/no_varchar_columns_test.exs
The scalar `:string` and `:varchar` patterns already included `remove`, because
a typed `remove` in a `change/0` migration re-adds the column on rollback. The
`{:array, :string}` pattern did not, so `remove :patterns, {:array, :string}`
could recreate a `varchar(255)[]` on rollback without tripping the guard.
Inconsistent with the two patterns beside it rather than a deliberate choice.
Raised by CodeRabbit on the PR.
Verified both formatted forms now match, and that `{:array, :text}` and
commented lines still do not.
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Closes the remainder of the
varchar(255)truncation class that #286 reported and PR #211 only partially fixed.Problem
A bare
:stringmigration column compiles tovarchar(255)on PostgreSQL but to unconstrainedTEXTaffinity on SQLite. Since SQLite is the default adapter for development, test, and most self-hosted deployments, a write longer than 255 characters passes locally and fails only on PostgreSQL withERROR 22001 (string_data_right_truncation).20260616120000_widen_metadata_text_columns.exsfixed the six columns that were actively crashing library scans. It hand-listed them, which is exactly why the rest of the class survived:subtitles.file_path(NOT NULL), built from the media path plus a.{lang}.srtsuffix, so strictly longer than themedia_files.paththat forced the original fiximport_sessions.scan_path,transcode_jobs.output_path,library_paths.pathimport_lists.sync_errorandplex_*.last_auth_error, both unbounded provider error text{:array, :string}columns, which arevarchar(255)[]A fully migrated database still carried 219 such columns. One is a live bug:
custom_formats.patternsisvarchar(255)[]whileMydia.Settings.CustomFormatexplicitly permits 500-character patterns, so a valid save fails on PostgreSQL and succeeds on SQLite.The same root cause shows up from the other side in CI, where deep worktree paths push ExUnit's
:tmp_dirpast 255 characters and produce PostgreSQL-only failures.Why widen everything
The schema declares 245
:stringcolumns across 59 migrations and never once passessize:. Novarcharlength here was chosen deliberately; every one is Ecto's accidental default. Length rules the application actually intends live in changesets viavalidate_length/3. So this removes an unintended constraint rather than relaxing a real one.Approach
The migration introspects
information_schemainstead of enumerating columns, so it covers every table regardless of migration history. Array-of-varchar is matched explicitly (data_type = 'ARRAY' AND udt_name = '_varchar') and widened toTEXT[], since arrays do not report as'character varying'.Oban and ErrorTracker are excluded from both the sweep and the assertion. Both own their schemas and ship their own migrations, so a dep bump that adds a varchar column must not fail a guard that has no mydia source to fix.
On SQLite it is a no-op, matching
20260223100000_fix_array_columns_for_postgres.exs.Cost is low:
varchar(n)→textis binary-coercible, so PostgreSQL skips the table rewrite and, absent a collation change, leaves dependent indexes intact. PR #211 already proved that againstmedia_files.pathand its UNIQUE btree index. No column here is a key: ids are:binary_idand no reference usestype: :string.downis a deliberate no-op rather than a narrowing. Narrowing hard-fails once a long value is stored, and a self-hosted operator rolling back a release must never hit a migration that refuses to run.Guards
test/mydia/repo/migrations/no_varchar_columns_test.exs, alongside the existingno_raw_table_rebuild_test.exs:test-postgresjob. Covers every form that produces a varchar: plain,{:array, :string}, parenthesisedadd(...),:varchar,references(type: :string),remove(whose rollback re-adds the column), andHelpers.modify_column_type/3.Pre-existing migrations are grandfathered by an explicit list, not a timestamp cutoff. Ecto selects pending migrations with
version not in applied_versions, so a branch cut before the sweep but merged after it runs after the sweep on an already-migrated database while running before it on a fresh CI one. A cutoff grandfathers exactly that file and lets the bug reach production with CI green. A staleness test keeps the list honest.Verification
custom_formats.patternsis nowtext[]with no length limit.mix precommit(compile,deps.unlock --unused,format --check-formatted,credo --strict, test): 7706 tests, 0 failures, 34 skipped.Review history
The first commit had three real defects, found in review and fixed in the second: array columns were invisible to all three mechanisms (so the schema test's green was actively misleading), the migration version collided with
20260813140000_widen_byte_size_columns_to_bigint.exson another branch (duplicate versions raiseEcto.MigrationErrorfrom the supervision-tree migrator, i.e. a boot failure on every install), and the timestamp cutoff had the grandfathering hole described above.Summary by CodeRabbit
Database Improvements
Documentation
Bug Fixes