fix(config): pluralize names ending in consonant+y as 'ies' (#81)

* fix(config): pluralize names ending in consonant+y as 'ies'

EnumLists used a simple suffix rule that handled x/s/z and ch/sh
but ignored the y -> ies rule. Type names like Policy or
HealthSeverity produced Policys and HealthSeveritys.

Apply the standard English rule: consonant + y drops the y and
appends ies, vowel + y just appends s. Move the heuristic into a
pluralize helper and cover the cases with a unit test.

* refactor(config): address review feedback

- Drop redundant c := c loop-variable rebind (Go 1.22+ scoping).
- Use testify/require.Equal in the table test.
- Generalize pluralize godoc to not tie it to EnumLists.
- Trim two redundant test cases.

* Add testdata

---------

Co-authored-by: Steven Masley <stevenmasley@gmail.com>

Author: evgeniy-scherbina

bindings/comments_test.go

@@ -0,0 +1,72 @@
+package bindings_test
+
+import (
+	"fmt"
+	"go/token"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/coder/guts/bindings"
+)
+
+func TestSyntheticComments(t *testing.T) {
+	b, err := bindings.New()
+	require.NoError(t, err)
+
+	str := bindings.LiteralKeyword(bindings.KeywordString)
+	param := &bindings.TypeParameter{
+		Name: bindings.Identifier{
+			Name:    "testparam",
+			Package: nil,
+			Prefix:  "",
+		},
+		Modifiers:   nil,
+		Type:        &str,
+		DefaultType: nil,
+		//SupportComments: bindings.SupportComments{},
+	}
+	//param.LeadingComment("a type parameter")
+
+	exp := &bindings.Interface{
+		Name: bindings.Identifier{
+			Name: "TestingInterface",
+		},
+		Modifiers: nil,
+		Fields:    nil,
+		Parameters: []*bindings.TypeParameter{
+			param,
+		},
+		Heritage: nil,
+		Source: bindings.Source{
+			File: "test.go",
+			Position: token.Position{
+				Filename: "test.go",
+				Offset:   0,
+				Line:     5,
+				Column:   10,
+			},
+		},
+	}
+
+	exp.AppendComment(bindings.SyntheticComment{
+		Leading:         true,
+		SingleLine:      true,
+		Text:            "hello world",
+		TrailingNewLine: false,
+	})
+
+	exp.AppendComment(bindings.SyntheticComment{
+		Leading:         false,
+		SingleLine:      true,
+		Text:            "goodbye world",
+		TrailingNewLine: false,
+	})
+
+	node, err := b.ToTypescriptNode(exp)
+	require.NoError(t, err)
+
+	ts, err := b.SerializeToTypescript(node)
+	require.NoError(t, err)
+	fmt.Println(ts)
+}

config/mutations.go

@@ -158,15 +158,7 @@ func EnumLists(ts *guts.Typescript) {
 			values = append(values, t)
 		}
 
-		// Pluralize the name
-		name := key + "s"
-		switch key[len(key)-1] {
-		case 'x', 's', 'z':
-			name = key + "es"
-		}
-		if strings.HasSuffix(key, "ch") || strings.HasSuffix(key, "sh") {
-			name = key + "es"
-		}
+		name := pluralize(key)
 
 		addNodes[name] = &bindings.VariableStatement{
 			Modifiers: []bindings.Modifier{},
@@ -384,6 +376,35 @@ func InterfaceToType(ts *guts.Typescript) {
 	})
 }
 
+// pluralize applies a best-effort English pluralization rule to a name
+// (for example "Policy" -> "Policies", "Box" -> "Boxes", "User" -> "Users").
+//
+// The heuristic only handles common regular cases. It does not try to
+// recognize already-plural inputs ("Updates" -> "Updateses") or irregular
+// plurals ("Person" -> "Persons", not "People").
+func pluralize(key string) string {
+	if key == "" {
+		return key
+	}
+	if strings.HasSuffix(key, "ch") || strings.HasSuffix(key, "sh") {
+		return key + "es"
+	}
+	switch key[len(key)-1] {
+	case 'x', 's', 'z':
+		return key + "es"
+	case 'y':
+		// consonant + y -> ies, vowel + y -> just s.
+		if len(key) >= 2 && !isVowel(key[len(key)-2]) {
+			return key[:len(key)-1] + "ies"
+		}
+	}
+	return key + "s"
+}
+
+func isVowel(b byte) bool {
+	return strings.IndexByte("aeiouAEIOU", b) >= 0
+}
+
 func isGoEnum(n bindings.Node) (*bindings.Alias, *bindings.UnionType, bool) {
 	al, ok := n.(*bindings.Alias)
 	if !ok {

config/pluralize_internal_test.go

@@ -0,0 +1,53 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPluralize(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		in   string
+		want string
+	}{
+		// Default: just add "s".
+		{"User", "Users"},
+		{"Audience", "Audiences"},
+
+		// Ends in x, s, z: add "es".
+		{"Box", "Boxes"},
+		{"Bus", "Buses"},
+		{"Buzz", "Buzzes"},
+
+		// Ends in ch, sh: add "es".
+		{"Church", "Churches"},
+		{"Bush", "Bushes"},
+
+		// Consonant + y: drop "y", add "ies".
+		{"Policy", "Policies"},
+		{"Category", "Categories"},
+		{"Story", "Stories"},
+		{"City", "Cities"},
+		{"HealthSeverity", "HealthSeverities"},
+
+		// Vowel + y: just add "s".
+		{"Day", "Days"},
+		{"Key", "Keys"},
+		{"Boy", "Boys"},
+
+		// Single-character edge cases.
+		{"", ""},
+		{"y", "ys"},
+		{"A", "As"},
+	}
+
+	for _, c := range cases {
+		t.Run(c.in, func(t *testing.T) {
+			t.Parallel()
+			require.Equal(t, c.want, pluralize(c.in))
+		})
+	}
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/coder/guts
 
-go 1.24.0
+go 1.24.4
 
 require (
 	github.com/dop251/goja v0.0.0-20241024094426-79f3a7efcdbd
@@ -11,16 +11,18 @@ require (
 )
 
 require (
+	github.com/Masterminds/semver/v3 v3.3.1 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
-	github.com/dlclark/regexp2 v1.11.4 // indirect
+	github.com/dlclark/regexp2 v1.11.5 // indirect
 	github.com/go-sourcemap/sourcemap v2.1.3+incompatible // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
 	github.com/google/pprof v0.0.0-20230207041349-798e818bf904 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/rogpeppe/go-internal v1.10.0 // indirect
+	github.com/rogpeppe/go-internal v1.14.1 // indirect
 	golang.org/x/mod v0.31.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/text v0.32.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,18 +1,18 @@
-github.com/Masterminds/semver/v3 v3.2.1 h1:RN9w6+7QoMeJVGyfmbcgs28Br8cvmnucEXnY0rYXWg0=
-github.com/Masterminds/semver/v3 v3.2.1/go.mod h1:qvl/7zhW3nngYb5+80sSMF+FG2BjYrf8m9wsX0PNOMQ=
+github.com/Masterminds/semver/v3 v3.3.1 h1:QtNSWtVZ3nBfk8mAOu/B6v7FMJ+NHTIgUPi7rj+4nv4=
+github.com/Masterminds/semver/v3 v3.3.1/go.mod h1:4V+yj/TJE1HU9XfppCwVMZq3I84lprf4nC11bSS5beM=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dlclark/regexp2 v1.11.4 h1:rPYF9/LECdNymJufQKmri9gV604RvvABwgOA8un7yAo=
-github.com/dlclark/regexp2 v1.11.4/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dlclark/regexp2 v1.11.5 h1:Q/sSnsKerHeCkc/jSTNq1oCm7KiVgUMZRDUoRu0JQZQ=
+github.com/dlclark/regexp2 v1.11.5/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
 github.com/dop251/goja v0.0.0-20241024094426-79f3a7efcdbd h1:QMSNEh9uQkDjyPwu/J541GgSH+4hw+0skJDIj9HJ3mE=
 github.com/dop251/goja v0.0.0-20241024094426-79f3a7efcdbd/go.mod h1:MxLav0peU43GgvwVgNbLAj1s/bSGboKkhuULvq/7hx4=
 github.com/fatih/structtag v1.2.0 h1:/OdNE99OxoI/PqaW/SuSK9uxxT3f/tcSZgon/ssNSx4=
 github.com/fatih/structtag v1.2.0/go.mod h1:mBJUNpUnHmRKrKlQQlmCrh5PuhftFbNv8Ys4/aAZl94=
 github.com/go-sourcemap/sourcemap v2.1.3+incompatible h1:W1iEw64niKVGogNgBN3ePyLFfuisuzeidWPMPWmECqU=
 github.com/go-sourcemap/sourcemap v2.1.3+incompatible/go.mod h1:F8jJfvm2KbVjc5NqelyYJmf/v5J0dwNLS2mL4sNA1Jg=
-github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
-github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/pprof v0.0.0-20230207041349-798e818bf904 h1:4/hN5RUoecvl+RmJRE2YxKWtnnQls6rQjjW5oV7qg2U=
 github.com/google/pprof v0.0.0-20230207041349-798e818bf904/go.mod h1:uglQLonpP8qtYCYyzA+8c/9qtqgA3qsXGYqCPKARAFg=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
@@ -26,16 +26,16 @@ github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsK
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
-github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
-github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/stretchr/testify v1.11.0 h1:ib4sjIrwZKxE5u/Japgo/7SJV3PvgjGiRNAvTVGqQl8=
 github.com/stretchr/testify v1.11.0/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
 golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
 golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
+golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
 golang.org/x/tools v0.40.0 h1:yLkxfA+Qnul4cs9QA3KnlFu0lVmd8JJfoq+E41uSutA=
 golang.org/x/tools v0.40.0/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
 golang.org/x/xerrors v0.0.0-20240903120638-7835f813f4da h1:noIWHXmPHxILtqtCOPIhSt0ABwskkZKjD3bXGnZGpNY=