Support package-names with dashes in them (#232)

Support package-names with dashes in them

We were smart about aliasing if you have name-collisions, but not if
your package name is something that's not a valid identifier, like
`"path/to/my-package"`, which Go for better or worse allows. Now we
remove all the invalid characters (in practice mainly dashes, dots, and
leading digits).

Fixes #231.

Test plan: make check

generate/generate_test.go

@@ -171,6 +171,10 @@ func TestGenerateWithConfig(t *testing.T) {
 			Generated:   "generated.go",
 			ContextType: "github.com/Khan/genqlient/internal/testutil.MyContext",
 		}},
+		{"CustomContextWithAlias", "", nil, &Config{
+			Generated:   "generated.go",
+			ContextType: "github.com/Khan/genqlient/internal/testutil/junk---fun.name.MyContext",
+		}},
 		{"StructReferences", "", nil, &Config{
 			StructReferences: true,
 			Generated:        "generated-structrefs.go",

generate/imports.go

@@ -2,14 +2,43 @@ package generate
 
 import (
 	"fmt"
+	"go/token"
 	"go/types"
 	"regexp"
 	"strconv"
 	"strings"
+	"unicode"
 )
 
+// makeIdentifier takes a string and returns a valid go identifier like it.
+//
+// If the string is an identifier, return the input. Otherwise, munge it to
+// make a valid identifier, which at worst (if the input is entirely emoji,
+// say) means coming up with one out of whole cloth. This identifier need not
+// be particularly unique; the caller may add a suffix.
+func makeIdentifier(candidateIdentifier string) string {
+	if token.IsIdentifier(candidateIdentifier) {
+		return candidateIdentifier
+	}
+
+	var goodChars strings.Builder
+	for _, c := range candidateIdentifier {
+		// modified from token.IsIdentifier
+		if unicode.IsLetter(c) || c == '_' ||
+			// digits only valid after first char
+			goodChars.Len() > 0 && unicode.IsDigit(c) {
+			goodChars.WriteRune(c)
+		}
+	}
+	if goodChars.Len() > 0 {
+		return goodChars.String()
+	}
+
+	return "alias"
+}
+
 func (g *generator) addImportFor(pkgPath string) (alias string) {
-	pkgName := pkgPath[strings.LastIndex(pkgPath, "/")+1:]
+	pkgName := makeIdentifier(pkgPath[strings.LastIndex(pkgPath, "/")+1:])
 	alias = pkgName
 	suffix := 2
 	for g.usedAliases[alias] {

generate/imports_test.go

@@ -0,0 +1,42 @@
+package generate
+
+import (
+	"go/token"
+	"testing"
+)
+
+func TestMakeIdentifier(t *testing.T) {
+	tests := []struct {
+		testName string
+		input    string
+		expected string
+	}{
+		{"GoodIdentifier", "myIdent", "myIdent"},
+		{"GoodIdentifierNumbers", "myIdent1234", "myIdent1234"},
+		{"NumberPrefix", "1234myIdent", "myIdent"},
+		{"OnlyNumbers", "1234", "alias"},
+		{"Dashes", "my-ident", "myident"},
+		// Note: most Go implementations won't actually allow
+		// this package-path, but the spec is pretty vague
+		// so make sure to handle it.
+		{"JunkAnd", "my!!\\\\\nident", "myident"},
+		{"JunkOnly", "!!\\\\\n", "alias"},
+		{"Accents", "née", "née"},
+		{"Kanji", "日本", "日本"},
+		{"EmojiAnd", "ident👍", "ident"},
+		{"EmojiOnly", "👍", "alias"},
+	}
+
+	for _, test := range tests {
+		test := test
+		t.Run(test.testName, func(t *testing.T) {
+			actual := makeIdentifier(test.input)
+			if actual != test.expected {
+				t.Errorf("mismatch:\ngot:  %s\nwant: %s", actual, test.expected)
+			}
+			if !token.IsIdentifier(actual) {
+				t.Errorf("not a valid identifier: %s", actual)
+			}
+		})
+	}
+}

generate/testdata/snapshots/TestGenerateWithConfig-CustomContextWithAlias-testdata-queries-generated.go

@@ -0,0 +1,68 @@
+// Code generated by github.com/Khan/genqlient, DO NOT EDIT.
+
+package queries
+
+import (
+	"context"
+
+	"github.com/Khan/genqlient/graphql"
+	junkfunname "github.com/Khan/genqlient/internal/testutil/junk---fun.name"
+)
+
+// Check that context_type from genqlient.yaml implements context.Context.
+var _ context.Context = (junkfunname.MyContext)(nil)
+
+// SimpleQueryResponse is returned by SimpleQuery on success.
+type SimpleQueryResponse struct {
+	// user looks up a user by some stuff.
+	//
+	// See UserQueryInput for what stuff is supported.
+	// If query is null, returns the current user.
+	User SimpleQueryUser `json:"user"`
+}
+
+// GetUser returns SimpleQueryResponse.User, and is useful for accessing the field via an interface.
+func (v *SimpleQueryResponse) GetUser() SimpleQueryUser { return v.User }
+
+// SimpleQueryUser includes the requested fields of the GraphQL type User.
+// The GraphQL type's documentation follows.
+//
+// A User is a user!
+type SimpleQueryUser struct {
+	// id is the user's ID.
+	//
+	// It is stable, unique, and opaque, like all good IDs.
+	Id string `json:"id"`
+}
+
+// GetId returns SimpleQueryUser.Id, and is useful for accessing the field via an interface.
+func (v *SimpleQueryUser) GetId() string { return v.Id }
+
+func SimpleQuery(
+	ctx junkfunname.MyContext,
+	client graphql.Client,
+) (*SimpleQueryResponse, error) {
+	req := &graphql.Request{
+		OpName: "SimpleQuery",
+		Query: `
+query SimpleQuery {
+	user {
+		id
+	}
+}
+`,
+	}
+	var err error
+
+	var data SimpleQueryResponse
+	resp := &graphql.Response{Data: &data}
+
+	err = client.MakeRequest(
+		ctx,
+		req,
+		resp,
+	)
+
+	return &data, err
+}
+