Switch order of String literals to prevent NullPointerException

[pixeebot]

This change defensively switches the order of literals in comparison expressions to ensure that no null pointer exceptions are unexpectedly thrown. Runtime exceptions especially can cause exceptional and unexpected code paths to be taken, and this can result in unexpected behavior.

Both simple vulnerabilities (like information disclosure) and complex vulnerabilities (like business logic flaws) can take advantage of these unexpected code paths.

Our changes look something like this:

  String fieldName = header.getFieldName();
  String fieldValue = header.getFieldValue();
- if(fieldName.equals("requestId")) {
+ if("requestId".equals(fieldName)) {
    logRequest(fieldValue);
  }

More reading

• http://cwe.mitre.org/data/definitions/476.html
• https://en.wikibooks.org/wiki/Java_Programming/Preventing_NullPointerException
• https://rules.sonarsource.com/java/RSPEC-1132/

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[sbrannen]

Although I understand the intention of this PR, this particular change cannot possibly avoid a NullPointerException, since the preceding if-statement has already invoked a method on engineId.

Instead of making changes like this one, I think we should rather focus on specifying that org.junit.platform.engine.TestEngine.getId() may never return null, and we can consider introducing a Preconditions.notNull(testEngine.getId()) check if we are concerned about that.

[sbrannen]

See:

• 2898164
• 941f80d

[marcphilipp]

@pixeebot @ryandens Here's some feedback on the java/switch-literal-first codemod