feat: Add stubs for more of the reflect package

[kyleconroy]

With this change, tinygo can now compile and pass the example_test.go for the text/template package.

@dgryski @dkegel-fastly How do I add the example_test.go to tinygo?

Replaces #2574

[dkegel-fastly]

Simplest might be to add testdata/template.{go,txt} and then add "template.go" into main_test.go's list of tests.

template.txt should contain the expected output.

[kyleconroy]

Looks like my initial testing was incorrect. example_test.go does not run with this patch. Instead it fails with the following error:

Dear panic: unimplemented: (reflect.Value).MethodByName()

I didn't realize that example_test.go doesn't have tests in it, only two examples. By default, tinygo test doesn't run these.

[dkegel-fastly]

You could add a smoke test instead a la #2565

Then once you get that other fix pushed upstream, maybe add testcases/protobuf.{go,txt}.

[dgryski]

Yeah, I ran into exactly that MethodByName (or FieldByName) panic during my testing.

[dkegel-fastly]

That windows failure looks spurious.

[kyleconroy]

Smoke test added, let me know if you'd like it in a different place / format.

[dkegel-fastly]

You also need to invoke it from Makefile's smoketest rule, otherwise it doesn't get run.

Most of the tests in that rule specify a target, but this one probably shouldn't.

Note that the tinygo maintainers may have different feedback; I have added a smoke test, but am a relative newcomer.

[kyleconroy]

I added the line but forgot to commit it. Will fix

[kyleconroy]

Maybe I need to specify a target in the Makefile?

cd tests/text/template/smoke && /go/bin/tinygo test -c && rm smoke.test
# os
/home/circleci/project/src/os/dir_unix.go:44:36: undeclared name: readdirMode
/home/circleci/project/src/os/dir_unix.go:44:76: undeclared name: DirEntry
/home/circleci/project/src/os/file_unix.go:139:56: undeclared name: DirEntry
/home/circleci/project/src/os/dir_unix.go:116:14: undeclared name: readdirName
/home/circleci/project/src/os/dir_unix.go:118:21: undeclared name: readdirDirEntry
/home/circleci/project/src/os/file_unix.go:145:29: undeclared name: testingForceReadDirLstat
/home/circleci/project/src/os/file_unix.go:154:24: info.Mode().Type undefined (type FileMode has no field or method Type)
FAIL
make: *** [Makefile:311: smoketest] Error 1

Exited with code exit status 2

[dankegel]

Heh. Nope! Note which build failed.... it's the go 1.15 build. Perhaps you took your example from go 1.16 or newer, and it needs 1.16-only features, who knows. It's probably fine to exclude 1.15 on this file. I think the syntax is:

--- a/tests/text/template/smoke/smoke_test.go
+++ b/tests/text/template/smoke/smoke_test.go
@@ -1,3 +1,6 @@
+//go:build go1.16
+// +build go1.16
+
 // Copyright 2011 The Go Authors. All rights reserved.

The other problem is that you have not turned it into a test, so it's still not compiling the examples.
(Adding support for examples to tinygo wouldn't be all that hard, but nobody has gotten around to it.)
To turn it into a test, just change the signatures and names, e.g.

-func ExampleTemplate() {
+func TestTemplate(t *testing.T) {

and of course import testing, and fix the one variable name clash and any lint problems that pop up.

They won't be the greatest tests of all, but they will do just fine as a "does it compile at all" smoke test.

[kyleconroy]

• Updated example_test.go to the version for Go 1.15
• Changed the examples to tests

[dkegel-fastly]

Oh, apologies, it's not the version of go you got the code from, it's the version the user is running (and thus which go code they're getting.)
So you'll still need the build constraint.

[dkegel-fastly]

Oh, ffs:

package github.com/tinygo-org/tinygo/tests/text/template/smoke: build constraints exclude all Go files in /home/circleci/project/tests/text/template/smoke

So add a pacifier test file, I guess.

[kyleconroy]

Okay I give up lol. Is there a better place / way for me to add these tests?

[dkegel-fastly]

heh. Hang on, let me give it a shot.

[kyleconroy]

@dkegel-fastly any luck?

[dkegel-fastly]

Been swamped, will try in the morning.

[dkegel-fastly]

luck. See last commit in https://github.com/dkegel-fastly/tinygo/commits/compile-text-template

empty.go and the build constraint can be deleted once we drop support for go 1.15, I think.

[kyleconroy]

@dankegel tests are now passing. Is this ready to merge?

[dkegel-fastly]

No, now it's ready for code review :-) Congrats on getting this far, though!

This is the point I often get stuck at, especially when a maintainer is on vacation...

[dgryski]

Thanks! Can you rebase and squash some of these commits?

cc @deadprogram I suppose we can always squash on merge too.

[kyleconroy]

@dgryski Done!

[dgryski]

LGTM

[dkegel-fastly]

Now that this is merged, are you going to open an issue on vtprotobuf as mentioned earlier ( #2574 (comment) ) ?