internal/ethapi: add testcases for blobTx

[jsvisa]

No description provided.

[jsvisa]

@fjl ptal, thanks

[fjl]

It's good that you're adding tests, but I'm not so happy to have all of these test vectors inline as strings. If we ever change the API again, a lot of hand-editing will need to happen. So I would like to ask you, if you have time, to restructure these tests using testdata files. It can be done as follows:

• In the test case struct, add a new string field with a name. This name can be used as the "test name", but also as the filename of a JSON file in testdata.
• During test execution, if a special environment variable is set (e.g. GENERATE_TEST), the output that you are comparing against should be written to the testdata file. Use json.MarshalIndent to write a readable version.
• If the environment variable is not set, the test should load the file and compare the text just like now.

[jsvisa]

It's good that you're adding tests, but I'm not so happy to have all of these test vectors inline as strings. If we ever change the API again, a lot of hand-editing will need to happen. So I would like to ask you, if you have time, to restructure these tests using testdata files. It can be done as follows:

• In the test case struct, add a new string field with a name. This name can be used as the "test name", but also as the filename of a JSON file in testdata.

• During test execution, if a special environment variable is set (e.g. GENERATE_TEST), the output that you are comparing against should be written to the testdata file. Use json.MarshalIndent to write a readable version.

• If the environment variable is not set, the test should load the file and compare the text just like now.

Sounds good to me, I'll adjust them this weekend

[jsvisa]

@fjl, please take another look, thanks.

use the env variable WRITE_TEST_FILES from

go-ethereum/rlp/rlpgen/gen_test.go

Line 68 in 40ceae9

if os.Getenv("WRITE_TEST_FILES") != "" {