Implement .rultor.yml Validation, Remove Invalid Puzzle

[original-brownbear]

Problem

We currently do not really validate the .rultor.yml file. This was a feature desired in #570 and led to the addition of the validation snippet in this code ( and some now ignored tests ) in this PR:

    /**
     * Get .rultor.yml file.
     * @return Its content
     * @throws IOException If fails
     */
    private String yml() throws IOException {
        final String yml;
        if (this.repo.contents()
            .exists(GithubProfile.FILE, this.branch)) {
            yml = new String(
                new Content.Smart(
                    this.repo.contents().get(GithubProfile.FILE)
                ).decoded(),
                CharEncoding.UTF_8
            );
        } else {
            yml = "";
        }
        final List<String> msg = this.validate(yml);
        if (!msg.isEmpty()) {
            throw new Profile.ConfigException(
                String.format(
                    "`%s` is not valid according to schema:\n``%s``",
                    GithubProfile.FILE,
                    Joiner.on('\n').join(msg)
                )
            );
        }
        return yml;
    }

    /**
     * Validate rultor config YAML according to schema.
     * @param yml Rultor YAML config
     * @return Validation result message, empty list means validation succeeded.
     * @todo #570:30min Implement validation using Kwalify library in separate
     *  class called ValidYaml, move this method to that class and move tests
     *  from GitHubProfileValidationTest to ValidYamlTest. Remember about
     *  removing PMD suppress below.
     */
    @SuppressWarnings("PMD.UnusedFormalParameter")
    private List<String> validate(final String yml) {
        return Collections.emptyList();
    }

There are a few problems here now:

• We still don't have YAML validation :)
• Using the Kwalify library is not a valid approach anymore looking the official site for it, it is clear the library is not maintained anymore.
• "%sis not valid according to schema:\n``%s``" should be reworded. "according to schema" (what schema?) and then listing the issues after is neither correct English nor user friendly.

Expected Solution

A solution to this issue needs to:

• Move the validation to com.rultor.profiles.GithubProfile#read or the com.rultor.profiles.YamlXML#get to com.rultor.profiles.GithubProfile#yml so that it actually runs after the yaml has been parsed, not on the string. ( the current puzzle being solved directly would otherwise entail parsing the YAML twice!)
  • No need to add a new parser library either we already have this one in the pom.xml:

        <dependency>
            <groupId>org.yaml</groupId>
            <artifactId>snakeyaml</artifactId>
            <version>1.16</version>
        </dependency>

• Validate the parse result to not contain undocumented keys according to this document or invalid data types for valid keys.
  • Ensure that invalid entries and the resulting broken build, lead to output to the user clearly indicating that entry X in line Y is invalid and needs to be removed/fixed for the build to work. Also add a link to http://doc.rultor.com/reference.html to the output.
• Remove the Puzzle shown above and linked to GithubProfile.java:247-250: Implement validation using Kwalify library... #699, it makes no sense anymore the way it is worded.

[original-brownbear]

@alex-palevsky this is a bug.

[alex-palevsky]

@alex-palevsky this is a bug.

@original-brownbear tag bug added to this issue

[alex-palevsky]

@original-brownbear since there is no milestone yet I set it to "2.0"

[alex-palevsky]

@original-brownbear thanks for the report, I topped your acc for 30 mins, payment ID AP-0UT81441V1306624N

[original-brownbear]

@alex-palevsky this is postponed.

[alex-palevsky]

@alex-palevsky this is postponed.

@original-brownbear OK, I put "postponed" label here

[alex-palevsky]

@alex-palevsky this is postponed.

@original-brownbear I will try to find someone else