render diff for readme checks

[efd6]

This renders the difference between the stored and rendered readme files. Like so:

[2022-09-27T07:35:28.126Z] README.md is outdated. Rebuild the package with 'elastic-package build'
[2022-09-27T07:35:28.126Z]   strings.Join({
[2022-09-27T07:35:28.126Z]   	... // 49896 identical bytes
[2022-09-27T07:35:28.126Z]   	"| host.os.name | Operating system name, without the version. | k",
[2022-09-27T07:35:28.126Z]   	"eyword |\n| host.os.name.text | Multi-field of `host.os.name`. | ",
[2022-09-27T07:35:28.126Z] - 	"match_only_",
[2022-09-27T07:35:28.126Z]   	"text |\n| host.os.platform | Operating system platform (such cent",
[2022-09-27T07:35:28.126Z]   	"os, ubuntu, windows). | keyword |\n| host.os.version | Operating ",
[2022-09-27T07:35:28.126Z]   	... // 10306 identical bytes
[2022-09-27T07:35:28.126Z]   }, "")
[2022-09-27T07:35:28.126Z] Error: checking package failed: checking readme files are up-to-date failed: files do not match

This is important due to differential behaviour between CI and local elastic-package build.

[elasticmachine]

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• Start Time: 2022-09-28T12:06:23.057+0000

• Duration: 32 min 50 sec

Test stats 🧪

Test	Results
Failed	0
Passed	831
Skipped	0
Total	831

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To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (34/34)	💚
Files	66.142% (84/127)	👍
Classes	61.111% (110/180)	👍
Methods	48.77% (357/732)	👍
Lines	32.097% (3218/10026)	👎 -0.038
Conditionals	100.0% (0/0)	💚

[efd6]

/test

[jsoriano]

This is important due to differential behaviour between CI and local elastic-package build.

To what different behavior do you refer?

When this error happens, locally you can run elastic-package build, and see with git diff what are the changes.

[2022-09-27T07:35:28.126Z] README.md is outdated. Rebuild the package with 'elastic-package build'
[2022-09-27T07:35:28.126Z] strings.Join({
[2022-09-27T07:35:28.126Z] ... // 49896 identical bytes
[2022-09-27T07:35:28.126Z] "| host.os.name | Operating system name, without the version. | k",
[2022-09-27T07:35:28.126Z] "eyword |\n| host.os.name.text | Multi-field of host.os.name. | ",
[2022-09-27T07:35:28.126Z] - "match_only_",

Is it expected for this diff to show the strings.Join(...... text? This looks like non evaluated Go code. Would it be possible to show a unified diff?

[efd6]

At the moment the builds on CI are consistently rendering readme files differently to how they are rendered locally.

The diff is as it's intended to be, I would not like to see huge diffs here, just enough to be able to get an idea of what is being misrendered.

Docs for the format are here https://pkg.go.dev/github.com/google/go-cmp/cmp#Diff.

[jsoriano]

/test

[efd6]

If you would prefer, we can do what we have in the pipeline result diffing

	var buf bytes.Buffer
	err = difflib.WriteUnifiedDiff(&buf, difflib.UnifiedDiff{
		A:        difflib.SplitLines(string(existing)),
		B:        difflib.SplitLines(string(rendered)),
		FromFile: "want",
		ToFile:   "got",
		Context:  3, // Maybe less context though.
	})
	return false, buf.String(), err

[jsoriano]

Yes, I think I would prefer a more standard diff, could you give it a try and show an example?

[efd6]

Sure. I'm thinking a context of 2 would be enough for this situation. WDYT?

[jsoriano]

Agree with a small diff 👍

[efd6]

I tried 2 and I think it's still too much. This is 1:

Format the package
Done
Lint the package
buildmanifest.Dependencies{ECS:buildmanifest.ECSDependency{Reference:"git@v8.4.0-rc1"}}
README.md is outdated. Rebuild the package with 'elastic-package build'
--- want
+++ got
@@ -308,3 +308,2 @@
 | rsa.internal.cid | This is the unique identifier used to identify a NetWitness Concentrator. This key should never be used to parse Meta data from a session (Logs/Packets) Directly, this is a Reserved key in NetWitness | keyword |
-| rsa.internal.data | Deprecated key defined only in table map. | keyword |
 | rsa.internal.dead | Deprecated key defined only in table map. | long |
@@ -342,4 +341,2 @@
 | rsa.internal.msg | This key is used to capture the raw message that comes into the Log Decoder | keyword |
-| rsa.internal.msg_id | This is the Message ID1 value that identifies the exact log parser definition which parses a particular log session. This key should never be used to parse Meta data from a session (Logs/Packets) Directly, this is a Reserved key in NetWitness | keyword |
-| rsa.internal.msg_vid | This is the Message ID2 value that identifies the exact log parser definition which parses a particular log session. This key should never be used to parse Meta data from a session (Logs/Packets) Directly, this is a Reserved key in NetWitness | keyword |
 | rsa.internal.node_name | Deprecated key defined only in table map. | keyword |
@@ -347,3 +344,2 @@
 | rsa.internal.obj_id | Deprecated key defined only in table map. | keyword |
-| rsa.internal.obj_server | Deprecated key defined only in table map. | keyword |
 | rsa.internal.obj_val | Deprecated key defined only in table map. | keyword |
Error: checking package failed: checking readme files are up-to-date failed: files do not match