Bun's limits

The package runs on Bun’s own client, and leans on what it does. Where Bun falls short, the package works around it, or the types say what Bun reads. Where a row names an issue, the package’s tests pin what Bun does today, and fail once Bun fixes it, so that the workaround goes with the bug.

Values

Bun	the package	left to you
reads an array of an enum, of a domain, of a composite type, of a range or a multirange of one’s own or of an extension’s type as its literal, such as "{a,b}" (#41040)	types such a column ArrayLiteral<E>: read as that string, written as an array	parse the string where the elements are needed
binds a JavaScript array to an array of an enum, of a domain, of a composite type, of a range or a multirange of one’s own or of an extension’s type as its elements joined by commas, which Postgres refuses	writes an array to a column of arrays, and to a parameter of a query file, as the literal Postgres reads	in raw SQL, cast the array to one of a built-in type first: ${moods}::text[]::mood[]
binds a JavaScript array to a json[] or a jsonb[] with null as JSON’s null, and an array element as an array of more dimensions	writes the JSON of each element, and null as NULL
binds -0 in a JavaScript array as 0	writes it as -0
binds a Date of a year past 9999 or before 1 as toISOString() writes it, such as +010000-01-01, which a date and an array of dates or timestamps refuse	writes a Date as its ISO text, which a date reads of any year
binds an invalid Date as the text Invalid Date, which Postgres refuses	throws a RangeError before anything is sent
reads an int4[] or a float4[] as an Int32Array or a Float32Array when a query has parameters	reads it as an array
reads a float4 with parameters as its 32-bit value, such as 1.100000023841858 for 1.1		store what is compared or shown as float8 or numeric
reads 'infinity' and '-infinity' of a timestamp or a date as the numbers Infinity and -Infinity	says so in the generated types	check for a number where a column may hold them
stores a string bound to json or jsonb as a JSON string (#28819)	types the column to take an object or an array, so a value passed through JSON.stringify does not compile

The client

Bun	the package	left to you
before 1.4.4, read an array of uuid, of a range and of more types as its literal; before 1.4.3, could hand a query the rows of another after a failure on the same connection	database() throws on a Bun older than 1.4.4
takes PGDATABASE, when it is set, over the database a URL names (#45276)	gives Bun the URL’s database apart from the URL	give a client of your own its database too
connects without TLS when neither the URL nor PGSSLMODE names an sslmode, where Postgres’s own clients try TLS first		name the mode: TLS
has no cursor	stream() throws, saying so	read a long result in pages, by key
cannot describe a query without running it (#45277)	describes query files over a connection of its own, by host and port, with TLS as sslmode says	give types:generate a URL with a host and a port, not a unix socket, and an authority of your own in NODE_EXTRA_CA_CERTS
has query.cancel() cancel a query already sent on the server, where Kysely’s default ignore query lets one run to its end	cancels on abort only a query Bun has not sent yet, and leaves the server’s cancel to cancel query
may wait forever to close a connection the server ended	supports cancel query, not kill session

When Bun fixes one of these, a release of the package drops the workaround and says so in its notes.