Is This a Bug or Something Went Wrong? (Nested Array using v2)

[hollowaykeanho]

For TOML code that has array of data structure:

[Build]
Name = "publication build"

[[Build.Dependencies]]
Name = "command"
Program = "hugo"

And a Go structure:

type _tomlJob struct {
        Dependencies []map[string]interface{}
}

type TOMLParser struct {
        Build     *_tomlJob
}

Parsing Structure:

        s := struct {
                Build     *_tomlJob
        }{
                Build:     fx.Build,
        }

I got a parsing panic as follows:

panic: reflect: call of reflect.Value.Set on zero Value

goroutine 1 [running]:
reflect.flag.mustBeExportedSlow(0x199)
        /home/u0/Documents/monteur/.bin/golang/src/reflect/value.go:237 +0xc5
reflect.flag.mustBeExported(...)
        /home/u0/Documents/monteur/.bin/golang/src/reflect/value.go:231
reflect.Value.Set({0x6e38c0, 0xc0000ae088, 0xc0001023b8}, {0x0, 0x0, 0x6bcd40})
        /home/u0/Documents/monteur/.bin/golang/src/reflect/value.go:1900 +0x9f
github.com/pelletier/go-toml/v2.(*decoder).handleArrayTableCollection(0xc0000bf880, {0x1, 0xc0001023b8}, {0x6bcd40, 0xc0000a6280, 0x5})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:340 +0x50e
github.com/pelletier/go-toml/v2.(*decoder).handleKeyPart(0xc0000bf880, {0x1, 0xc0001023b8}, {0x6f0c40, 0xc0000a6270, 0xc0000bf880}, 0xc0000bf698, 0x73c2e0)
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:439 +0x5fb
github.com/pelletier/go-toml/v2.(*decoder).handleArrayTablePart(0xc0000a6270, {0x1, 0xc0001023b8}, {0x6f0c40, 0xc0000a6270, 0xc0000fea00})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:478 +0x6c
github.com/pelletier/go-toml/v2.(*decoder).handleArrayTable(0xc0000bf728, {0x1, 0xc0001023b8}, {0x6f0c40, 0xc0000a6270, 0x78e2a0})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:252 +0x71
github.com/pelletier/go-toml/v2.(*decoder).handleRootExpression(0xc0000bf880, 0xc000102380, {0x6f0c40, 0xc0000a6270, 0x70})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:234 +0xf7
github.com/pelletier/go-toml/v2.(*decoder).fromParser(0xc0000bf880, {0x6f0c40, 0xc0000a6270, 0x99c380})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:192 +0xa9
github.com/pelletier/go-toml/v2.(*decoder).FromParser(0xc0000bf880, {0x6bfe40, 0xc0000a6270})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:177 +0xf8
github.com/pelletier/go-toml/v2.(*Decoder).Decode(0xc0000bf930, {0x6bfe40, 0xc0000a6270})
        /home/u0/Documents/monteur/pkg/monteur/internal/endec/toml/internal/go-toml/unmarshaler.go:104 +0x171

If I change [[Build.Dependencies]] into [[Dependencies]], everything works fine. I need the Dependencies to be under Build because there are many jobs like Build, Publish, ... which have their respective dependencies.

Is this expected?

[hollowaykeanho]

Same issue even with initialized structure:

        fx.Build = &_tomlJob{
                Name:         "",
                Dependencies: []map[string]interface{}{},
        }

[pelletier]

Hi! From what I can tell your code should work. This seems like a bug.

[pelletier]

This should be fixed as of 79e78b2. Let me know if it works for you!

[hollowaykeanho]

Noted.. Let me pull the latest and test it out for you.

[hollowaykeanho]

This may sound silly but... how do you go get the bleeding edge of branch v2 since the patch is still not in a released version?

[hollowaykeanho]

Tested by setting require clause github.com/pelletier/go-toml/v2 c862c344b302d865a2db7db2dadf09b7bfed6c52 and pulled to latest with nested data structure, everything works fine.

[pelletier]

Thanks for checking!

In case you need it in the future, here's the way I recommend to use a specific version of go-toml (or any go lib for that matter): #672 (reply in thread)