comment_test.go

package exhaustive

import (
	"go/ast"
	"go/parser"
	"go/token"
	"testing"
)

func TestIsGeneratedFile(t *testing.T) {
	t.Run("generated", func(t *testing.T) {
		const source = `
	// Code generated by some thing. DO NOT EDIT.

package foo
func f() {
}`
		f, err := parser.ParseFile(token.NewFileSet(), "", source, parser.ParseComments)
		assertNoError(t, err)
		if !isGeneratedFile(f) {
			t.Errorf("unexpectedly false")
		}
	})

	t.Run("not generated", func(t *testing.T) {
		const source = `package foo
func f() {
}`
		f, err := parser.ParseFile(token.NewFileSet(), "", source, parser.ParseComments)
		assertNoError(t, err)
		if isGeneratedFile(f) {
			t.Errorf("unexpectedly true")
		}
	})
}

func TestDirectives(t *testing.T) {
	t.Run("no directives", func(t *testing.T) {
		commentGroups := []*ast.CommentGroup{
			{
				List: []*ast.Comment{
					{
						Text: "//exhauster:foo",
					},
				},
			},
			{
				List: []*ast.Comment{
					{
						Text: "//bar:value",
					},
					{
						Text: "Another comment",
					},
				},
			},
		}
		directives, err := parseDirectives(commentGroups)
		if err != nil {
			t.Errorf("unexpected error: %s", err)
		}
		if directives != 0 {
			t.Errorf("unexpected directives: %d", directives)
		}
	})

	t.Run("invalid directive", func(t *testing.T) {
		commentGroups := []*ast.CommentGroup{
			{
				List: []*ast.Comment{
					{
						Text: "//exhauster:foo",
					},
				},
			},
			{
				List: []*ast.Comment{
					{
						Text: "//exhaustive:enfocre",
					},
				},
			},
		}
		_, err := parseDirectives(commentGroups)
		if err == nil {
			t.Errorf("expectedly no error on invalid directive")
			return
		}
		if err.Error() != `invalid directive "enfocre"` {
			t.Errorf("unexpected error: %s", err)
		}
	})

	t.Run("conflicting enforcement directives", func(t *testing.T) {
		commentGroups := []*ast.CommentGroup{
			{
				List: []*ast.Comment{
					{
						Text: "//exhaustive:ignore",
					},
					{
						Text: "//exhaustive:enforce",
					},
				},
			},
			{
				List: []*ast.Comment{
					{
						Text: "//exhaustive:ignore-default-case-required",
					},
				},
			},
		}
		_, err := parseDirectives(commentGroups)
		if err == nil {
			t.Errorf("unexpectedly no error on conflicting directives")
			return
		}
		if err.Error() != `conflicting directives "ignore" and "enforce"` {
			t.Errorf("unexpected error: %s", err)
		}
	})

	t.Run("conflicting default case enforcement directives", func(t *testing.T) {
		commentGroups := []*ast.CommentGroup{
			{
				List: []*ast.Comment{
					{
						Text: "//exhaustive:enforce",
					},
				},
			},
			{
				List: []*ast.Comment{
					{
						Text: "//exhaustive:ignore-default-case-required",
					},
					{
						Text: "//exhaustive:enforce-default-case-required",
					},
					{
						Text: "//exhaustive:ignore-default-case-required",
					},
				},
			},
		}
		_, err := parseDirectives(commentGroups)
		if err == nil {
			t.Errorf("unexpectedly no error on conflicting directives")
			return
		}

	})

	t.Run("directives with trailing text and surrounding non-directives", func(t *testing.T) {
		commentGroups := []*ast.CommentGroup{
			{
				List: []*ast.Comment{
					{
						Text: "Nevermind this comment",
					},
					{
						Text: "//exhaustive:ignore foo",
					},
					{
						Text: "//exhaustive:enforce-default-case-required\tbar",
					},
					{
						Text: "This comment doesn't matter",
					},
				},
			},
		}

		directives, err := parseDirectives(commentGroups)
		if err != nil {
			t.Errorf("unexpected error: %s", err)
		}
		if directives != ignoreDirective|enforceDefaultCaseRequiredDirective {
			t.Errorf("unexpected directives: %d", directives)
		}
	})
}