Message Codes

Message Codes

Every message the engine produces carries three things: a Kind (Info, Warning, Error, Success, Step), an English Text, and — for every message born inside the engine — a stable Code plus the Args that were interpolated into it. The code and args are the message expressed as data.

The contract:

• Text is always English and is the only field a consumer has to understand.
• A presentation layer translates by code and falls back to Text when it has no translation. The engine itself has no notion of locale — it reports what happened, not how to word it. (The bundled UI ships a Turkish dictionary in app.js as the reference implementation.)
• Codes are a wire format. Renaming one silently drops a translation back to English — add a new code rather than repurposing an old one.
• {0}, {1} … in the templates correspond to Args in order. Translations may reorder them; they may not invent new ones.
• A message with no code carries text from outside the engine (a driver exception) and is shown as-is.

The definitive list lives in MessageCode.cs.

Steps

Code	English text
step.readingSchemas	Reading schemas
step.preflight	Preflight
step.copying	Copying data
step.verifyRowCounts	Verifying row counts
step.verifyForeignKeys	Verifying foreign key integrity

Plan

Code	English text
info.tablesToMigrate	{0} tables to migrate.
error.noTablesToCopy	No tables to copy — the source/target may be wrong, or the target has no schema.
error.columnNotSynthesizable	{0}.{1}: missing from the source, NOT NULL, and no safe default can be synthesized ({2}).
warn.sourceOnlyTable	Source table '{0}' does not exist in the target — its data will not be migrated.
error.sourceOnlyTable	…same, plus: If this is intentional, enable the 'allow source-only tables' option.

Preflight

Code	English text
info.preflightClean	Preflight clean: no NULL/length mismatches.
error.preflightNulls	{0}.{1}: target is NOT NULL but the source has {2} NULLs.
error.preflightLength	{0}.{1}: target is varchar({2}) but the longest source value is {3} characters.
warn.preflightAllowed	Proceeding because the risk was accepted — the copy may still fail midway.

Copy

Code	English text
info.tableCopied	{0}: {1} rows
info.copyFinished	Copy finished — {0} rows.
info.sequencesAligned	{0} identity sequences aligned.
warn.truncateCascade	TRUNCATE CASCADE also emptied {0} dependent tables: {1}. Tables with no source counterpart stay empty.
warn.truncateCascadeMore	…same, with a (+{2} more) tail when more than eight tables cascaded.
error.zeroRows	No rows were copied; the source is empty or wrong. Nothing was committed.

Verification

Code	English text
info.rowCountsMatch	All row counts match.
error.rowCountMismatch	{0}: source has {1} rows, target has {2}.
info.foreignKeysClean	{0} foreign keys checked, no orphan rows.
error.orphanRows	Orphan rows: {0} ({1}) → {2}: {3} rows ({4}).
error.verifyFailedRollback	Verification failed — rolling back, the target was not written.

Target database

Code	English text
error.targetDbNameMissing	The target connection string has no database name.
info.targetDbExists	Target database '{0}' already exists — left untouched.
success.targetDbCreated	Target database '{0}' created.
success.targetDbCreatedCollation	Target database '{0}' created (collation: {1}).
info.collationVerified	Collation verified: {0}
warn.collationMismatchAllowed	Target collation is '{0}' — expected ICU '{1}'. Proceeding because the mismatch was allowed.
error.collationMismatch	Target collation is '{0}' — expected ICU '{1}'. A wrong collation is silent: search and sort quietly misbehave.

PostgreSQL notices

Code	English text
info.postgresNotice	(pg) {0}

Outcomes

The final verdict of a run, carried on the result as well as the last progress line:

Code	English text
success.migrated	{0} rows migrated and verified.
success.verifyPassed	Verification passed.
fail.collationMismatch	Collation mismatch.
fail.schemaMismatch	Schema mismatch — details above.
fail.emptyIntersection	Empty intersection.
fail.verifyFailed	Verification failed.
fail.preflightUnresolved	Preflight mismatches were not resolved.
fail.zeroRows	Zero rows.
fail.targetDbNotReady	The target database could not be prepared.
fail.exception	The migration stopped with an exception.

Tokens

Two sentinel values arrive as arguments yet still need translating — a collation the server would not reveal. The double @ marks them: no ICU locale or PostgreSQL collation name begins with one, so a presentation layer can translate them on sight without risking a collision with real data.

Token	Meaning
@@unknown	The value was absent (server returned nothing)
@@unreadable	The value could not be read at all