catch four more class reference forms

A params.pp is only ever reached by inherits and $class::var, so changing one
resolved to no hosts at all.

- index inherits, $class::var reads and create_resources()
- match a defined type declared part-way along a line

README.md

@@ -202,7 +202,8 @@ pluginsynced to every agent and is treated the same way.
 Finding what applies a class means searching two places, not one:
 
 1. `.pp` files under `site/` and `modules/` for `include`, `contain`,
-   `class { '...': }`, capitalised resource references and defined-type usage.
+   `inherits`, `class { '...': }`, capitalised resource references,
+   `create_resources()`, `$class::var` reads and defined-type usage.
 2. `hieradata/**/*.{yaml,eyaml}` for the class as a list item under
    `hiera_include:`. `profiles::base` declares
    `($hiera_include - $hiera_exclude).include` with a `unique` merge across the

internal/impact/index.go

@@ -17,11 +17,16 @@ import (
 var manifestRoots = []string{"site", "modules"}
 
 var (
-	commentRe     = regexp.MustCompile(`(?m)#.*$`)
-	includeRe     = regexp.MustCompile(`\b(?:include|contain|require)\s*\(?\s*['"]?(?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]?`)
-	classParamRe  = regexp.MustCompile(`\bclass\s*\{\s*['"](?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]`)
-	classRefRe    = regexp.MustCompile(`\bClass\s*\[\s*['"](?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]`)
-	defineUseRe   = regexp.MustCompile(`(?m)^\s*(?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)+)\s*\{`)
+	commentRe    = regexp.MustCompile(`(?m)#.*$`)
+	includeRe    = regexp.MustCompile(`\b(?:include|contain|require|inherits)\s*\(?\s*['"]?(?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]?`)
+	classParamRe = regexp.MustCompile(`\bclass\s*\{\s*['"](?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]`)
+	classRefRe   = regexp.MustCompile(`\bClass\s*\[\s*['"](?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]`)
+	defineUseRe  = regexp.MustCompile(`(?m)(?:^|[^\w:$.])(?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)+)\s*\{`)
+	// $mod::params::thing reads a class variable, which is a dependency on the
+	// class that declares it.
+	scopeVarRe = regexp.MustCompile(`\$(?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)+)::[a-z_][a-z0-9_]*`)
+	// create_resources('mod::type', ...) names a defined type in a string.
+	createResRe   = regexp.MustCompile(`create_resources\s*\(\s*['"](?:::)?([a-z][a-z0-9_]*(?:::[a-z0-9_]+)*)['"]`)
 	resourceRefRe = regexp.MustCompile(`\b([A-Z][a-zA-Z0-9_]*(?:::[A-Z][a-zA-Z0-9_]*)+)\s*\[`)
 	assetRe       = regexp.MustCompile(`(?:template|epp|file)\s*\(\s*['"]([a-z0-9_]+/[^'"]+)['"]|puppet:///modules/([a-z0-9_]+/[^'"\s]+)`)
 	hieraBlockRe  = regexp.MustCompile(`(?m)^(hiera_include|hiera_exclude):\s*$((?:\n\s+-\s*\S+)*)`)
@@ -153,7 +158,7 @@ func references(body string) []string {
 			seen[name] = true
 		}
 	}
-	for _, re := range []*regexp.Regexp{includeRe, classParamRe, classRefRe, defineUseRe} {
+	for _, re := range []*regexp.Regexp{includeRe, classParamRe, classRefRe, defineUseRe, scopeVarRe, createResRe} {
 		for _, m := range re.FindAllStringSubmatch(body, -1) {
 			add(m[1])
 		}

internal/impact/resolve_test.go

@@ -123,3 +123,23 @@ func TestParseHieraListsRegexFallback(t *testing.T) {
 		t.Errorf("exclude = %v", exclude)
 	}
 }
+
+func TestResolveInheritsScopeVarCreateResourcesAndInlineDefine(t *testing.T) {
+	// Four reference forms a plain include grep misses: class inheritance,
+	// a $class::var read, create_resources() naming a type in a string, and a
+	// defined type declared part-way along a line.
+	tests := map[string]string{
+		"inherits":         "profiles::inherited",
+		"scope variable":   "profiles::scopevar",
+		"create_resources": "profiles::created",
+		"inline define":    "profiles::inline::thing",
+	}
+	want := []string{"k8s1", "k8s2", "web1"}
+	for name, class := range tests {
+		t.Run(name, func(t *testing.T) {
+			if got := resolvedHosts(t, class); !reflect.DeepEqual(got, want) {
+				t.Errorf("%s = %v, want %v", class, got, want)
+			}
+		})
+	}
+}

internal/impact/testdata/repo/site/profiles/manifests/created.pp

@@ -0,0 +1,2 @@
+define profiles::created () {
+}

internal/impact/testdata/repo/site/profiles/manifests/inherited.pp

@@ -0,0 +1,2 @@
+class profiles::inherited {
+}

internal/impact/testdata/repo/site/profiles/manifests/inline/thing.pp

@@ -0,0 +1,2 @@
+define profiles::inline::thing () {
+}

internal/impact/testdata/repo/site/profiles/manifests/leaf.pp

@@ -1,4 +1,12 @@
 class profiles::leaf {
+  $copied = $profiles::scopevar::thing
+  create_resources('profiles::created', {})
+
+  case $copied {
+    'x': { profiles::inline::thing { 'mid-line': } }
+    default: {}
+  }
+
   file { '/tmp/leaf':
     content => template('profiles/leaf/x.erb'),
     source  => 'puppet:///modules/profiles/leaf/y.txt',

internal/impact/testdata/repo/site/profiles/manifests/mid.pp

@@ -1,3 +1,3 @@
-class profiles::mid {
+class profiles::mid inherits profiles::inherited {
   include profiles::leaf
 }

internal/impact/testdata/repo/site/profiles/manifests/scopevar.pp

@@ -0,0 +1,3 @@
+class profiles::scopevar {
+  $thing = 'x'
+}