# settings: make mergeReviewProfiles pure (no in-place mutation)

`7e186be`→[main](/content/gh/entireio/cli/commits/main/index.html)·

dipree·1mo ago·2 files·+57 added/-11 removed

mergeReviewProfiles mutated its base map in place before returning it. Today's callers tolerate it (base is always the freshly loaded settings map), but an in-place merge helper is a footgun. Build and return a new map, leaving both inputs untouched. Adds a test for purity + override precedence.

## Sessions

28dcc15e4c3bView transcript

[?\ Checkout the hand off doc that I just added.Pi·Opus 4.8·3 steps](/content/gh/entireio/cli/session/019eca64-8c2c-7b00-90c6-3aa49738c497#timeline-28dcc15e4c3b/index.html)

## Changes

2

- cmd/entire/cli/settings

- Msettings.go+16/-11
  - Msettings_test.go+41

```
675 unmodified lines

// mergeReviewProfiles overlays src review profiles onto base by name. A profile
// from a higher-precedence layer overrides the same-named one from a lower
// layer, but profiles unique to each layer are all preserved. This lets a team
// keep shared profiles in .entire/settings.json while individuals add or
// override profiles in clone-local preferences or .entire/settings.local.json,
// without one layer hiding the others' profiles.
// mergeReviewProfiles overlays src review profiles onto base by name, returning
// a new map. A profile from a higher-precedence layer (src) overrides the
// same-named one from a lower layer (base), but profiles unique to each layer
// are all preserved. This lets a team keep shared profiles in
// .entire/settings.json while individuals add or override profiles in
// clone-local preferences or .entire/settings.local.json, without one layer
// hiding the others' profiles.
//
// Neither input map is mutated: callers (and the maps they own, e.g. a freshly
// loaded ClonePreferences) can rely on their maps being left untouched.
func mergeReviewProfiles(base, src map[string]ReviewProfileConfig) map[string]ReviewProfileConfig {
	if len(src) == 0 {
		if len(base) == 0 && len(src) == 0 {
			return base
		}
		if base == nil {
			base = map[string]ReviewProfileConfig{}
		}
		out := make(map[string]ReviewProfileConfig, len(base)+len(src))
		for name, cfg := range base {
			out[name] = cfg
		}
		for name, cfg := range src {
			base[name] = cfg
			out[name] = cfg
		}
		return base
	}
	return out
}

func applyClonePreferences(settings *EntireSettings, prefs *ClonePreferences) {
```

Mcmd/entire/cli/settings/settings.go+16/-11

```
1153 unmodified lines

t.Errorf("AlwaysPrompt = %q, want %q", cfg.AlwaysPrompt, "Be brief.")
	}
}

func TestMergeReviewProfiles_PureAndPrecedence(t *testing.T) {
	t.Parallel()
	base := map[string]ReviewProfileConfig{
		"general":  {Task: "base general"},
		"security": {Task: "base security"},
	}
	src := map[string]ReviewProfileConfig{
		"general": {Task: "override general"}, // overrides base
		"scratch": {Task: "src scratch"},      // unique to src
	}

out := mergeReviewProfiles(base, src)

// Merged result: src overrides same-named, both layers' unique profiles kept.
	if out["general"].Task != "override general" {
		t.Errorf("general = %q, want src override", out["general"].Task)
	}
	if out["security"].Task != "base security" {
		t.Errorf("security = %q, want base preserved", out["security"].Task)
	}
	if out["scratch"].Task != "src scratch" {
		t.Errorf("scratch = %q, want src-only profile kept", out["scratch"].Task)
	}

// Inputs must not be mutated.
	if _, leaked := base["scratch"]; leaked {
		t.Error("base was mutated: src profile leaked into it")
	}
	if base["general"].Task != "base general" {
		t.Errorf("base[general] mutated: %q", base["general"].Task)
	}
	if len(src) != 2 {
		t.Errorf("src mutated: len = %d, want 2", len(src))
	}

// Both empty returns without allocating a non-nil map surprise.
	if got := mergeReviewProfiles(nil, nil); got != nil {
		t.Errorf("merge(nil,nil) = %v, want nil", got)
	}
}
```