Print correct code location of failing table test

[ansd]

See #515 and #635 for motivation.

Given a test file

  1 package tabletests_test
  2
  3 import (
  4   . "github.com/onsi/ginkgo"
  5   . "github.com/onsi/ginkgo/extensions/table"
  6   . "github.com/onsi/gomega"
  7 )
  8
  9 var _ = Describe("Bar", func() {
 10   DescribeTable("table",
 11     func(i int) {
 12       Expect(i).To(Equal(0))
 13     },
 14     Entry("yolo1", 0),
 15     Entry("yolo2", 1),
 16     TableEntry{
 17       Description: "yolo3",
 18       Parameters:  []interface{}{1},
 19       Pending:     false,
 20       Focused:     false,
 21     },
 22   )
 23 })

Output before this PR:

$ ginkgo .
Running Suite: Tabletests Suite
===============================
Random Seed: 1587237068
Will run 3 of 3 specs

•
------------------------------
• Failure [0.000 seconds]
Bar
/Users/david/scratch/tabletests/bar_test.go:9
  table
  /Users/david/go/pkg/mod/github.com/onsi/ginkgo@v1.12.0/extensions/table/table.go:92
    yolo2 [It]
    /Users/david/go/pkg/mod/github.com/onsi/ginkgo@v1.12.0/extensions/table/table_entry.go:43

    Expected
        <int>: 1
    to equal
        <int>: 0

    /Users/david/scratch/tabletests/bar_test.go:12
------------------------------
• Failure [0.000 seconds]
Bar
/Users/david/scratch/tabletests/bar_test.go:9
  table
  /Users/david/go/pkg/mod/github.com/onsi/ginkgo@v1.12.0/extensions/table/table.go:92
    yolo3 [It]
    /Users/david/go/pkg/mod/github.com/onsi/ginkgo@v1.12.0/extensions/table/table_entry.go:43

    Expected
        <int>: 1
    to equal
        <int>: 0

    /Users/david/scratch/tabletests/bar_test.go:12
------------------------------

Output after this PR:

Running Suite: Tabletests Suite
===============================
Random Seed: 1587237050
Will run 3 of 3 specs

•
------------------------------
• Failure [0.000 seconds]
Bar
/Users/david/scratch/tabletests/bar_test.go:9
  table
  /Users/david/scratch/tabletests/bar_test.go:10
    yolo2 [It]
    /Users/david/scratch/tabletests/bar_test.go:15

    Expected
        <int>: 1
    to equal
        <int>: 0

    /Users/david/scratch/tabletests/bar_test.go:12
------------------------------
• Failure [0.000 seconds]
Bar
/Users/david/scratch/tabletests/bar_test.go:9
  table
  /Users/david/scratch/tabletests/bar_test.go:10
    yolo3 [It]
    /Users/david/scratch/tabletests/bar_test.go:10

    Expected
        <int>: 1
    to equal
        <int>: 0

    /Users/david/scratch/tabletests/bar_test.go:12
------------------------------

Notes:

1. If the user constructs the TableEntry directly instead of using one of the (F/P/X)Entry constructors (as done in the yolo3 example above), the code location of the failing TableEntry defaults to the surrounding DescribeTable since I didn't find a way to programmatically locate the TableEntry. If someone has a good idea, let me know.
2. I tried to be as much backwards compatible as possible. Although, I've not seen users constructing a TableEntry directly (most users use the (F/P/X)Entry constructors), the changes in here are backwards compatible if the users use a TableEntry composite literal with keyed fields. If however, users use a TableEntry with unkeyed fields (i.e. something like TableEntry{"yolo3", []interface{}{1}, false, false}), the changes in this PR will break them. In that case, they would need to name the fields or use the (F/P/X)Entry constructors.

[blgm]

I think I'm ok with TableEntry{"yolo3", []interface{}{1}, false, false} breaking because although it's possible to use Ginkgo like this, it's not the documented way, and it's not best practice to construct a struct this way as the definition is outside of your control.

[blgm]

Looks good to me!