The two new boolean options let api.Generate cover the writefiles loop
and the diff comparison that previously lived in cmd. The compile
command becomes Generate with neither flag set, generate maps to
Write: true, and diff maps to Diff: true.

While simplifying GenerateOptions:
* Drop MutateConfig — tests now express config mutations by writing a
  temporary configuration file via writeMutatedConfig and pointing
  GenerateOptions.File at it. The mutated config is parsed (always to
  v2 shape), forced to version "2", and round-tripped via yaml.
* Drop DisableProcessPlugins from the API surface; we will revisit how
  to express that constraint.
* Add MarshalJSON/MarshalYAML to AnalyzerDatabase so the parsed Config
  round-trips through yaml.Marshal cleanly, which is what the new test
  helper relies on.

cmd/diff.go is gone and cmd/generate.go is left with only the helpers
(readConfig, parse, printFileErr) other cmd commands still use.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ

Add an explicit allowlist of process-based plugin names to
api.GenerateOptions. Generate fails before any parse or codegen runs if
the configuration declares a process plugin whose name is not in the
list. The "Insecure" prefix mirrors crypto/tls.Config.InsecureSkipVerify
to flag the trust decision callers are making — process plugins execute
arbitrary local commands.

The CLI populates the allowlist by scanning the user's own config for
declared process plugins, so `sqlc generate`, `sqlc compile`, and
`sqlc diff` keep working. SQLCDEBUG=processplugins=0 still disables
process plugins by leaving the allowlist nil.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ

The struct collapses to five fields: Config (io.Reader), Stderr, Write,
Diff, InsecureProcessPluginNames. api.Generate parses the config from
the reader and treats every relative path in it as relative to the
current working directory.

CLI: each command opens the config file, reads its bytes, parses it once
to extract declared process-plugin names, then chdirs to the config's
directory before invoking api.Generate. Single-process so chdir is fine.

Tests: a new mutatedConfigBytes helper parses the test's sqlc.yaml,
forces version "2", rewrites every schema/queries/output path to be
absolute relative to the test directory, and re-encodes as YAML — so
api.Generate works without knowing the source directory. Optional
mutate callback applies extra changes (managed-db servers etc.) and
also drops a temp file alongside the original for cmd.Vet which still
takes a config path.

cmd/process.go and cmd/vet.go now skip joining their dir parameter when
the config-supplied path is already absolute.

KNOWN ISSUE: TestReplay parse-error tests and the diff_output tests
fail because the api now emits absolute paths in error messages and
unified-diff labels (no config-dir context to strip). Either add a
BaseDir hint back to GenerateOptions or update the affected test
expectations to match.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ

Restore the dir context that vanished with the io.Reader switch, but as
a single optional field. BaseDir is the directory relative paths in the
config (schema, queries, output) are resolved against, and the prefix
stripped from file paths shown in parse errors and diff labels. When
empty, BaseDir defaults to the current working directory.

A small resolvePath helper sits in api/generate.go and is called from
processQuerySets and ProcessResult; absolute paths pass through
unchanged. Parse errors and diff labels reuse the same BaseDir for
relative formatting.

Side-effects:
* The endtoend tests no longer pre-rewrite paths to absolute — they
  just pass BaseDir = test directory. The absolutizePaths helper is
  gone.
* The CLI sets BaseDir to the config's directory (returned by
  loadConfig) but keeps the chdir for now since other cmd paths
  (vet, push) still use cwd-relative resolution.

Tradeoff vs. the strictly-cosmetic option: GenerateOptions still has
six fields, but BaseDir's semantics are coherent with how it's used
(resolution + label) and library callers don't need to chdir or
hand-rewrite paths.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ

t.Setenv restores the previous value when the test exits, which avoids
leaking SQLC_DUMMY_VALUE and the per-example VET_TEST_* URIs into other
tests in the same process.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ

Mirror how the real CLI populates cmd.Env: t.Setenv every entry from
exec.json's Env map and then call opts.DebugFromEnv/ExperimentFromEnv.
This generalises to any env var a test wants to set (not just
SQLCDEBUG/SQLCEXPERIMENT) and keeps the test path closer to the
production code path.

https://claude.ai/code/session_01RCzB2JR5Y5ScFDUmwcxGVZ