Write codes with heart. Pursue clean, simplified and extremely elegant codes. Agree with concepts in <Refactoring: Improving the Design of Existing Code> and <Clean Code: A Handbook of Agile Software Craftsmanship>.
Be familiar with codes already had, to keep consistent with the style and use.
Highly reusable, no duplicated codes or configurations.
Delete codes out of use in time.
Contributor Covenant Submitting of Conduct
Make sure Maven build process success. Run mvn -T 1C clean install or ./mvnw -T 1C clean install command in shell to start Maven build process. On which directory to run Maven build process, there are 2 alternatives, we could select one of them: 1) if we’re not familiar with Apache ShardingSphere, then we could run it on project root directory, 2) if we know which modules will be affected by the changes, then we could run it on these modules to save build time.
Make sure the test coverage rate is not lower than the master branch.
Careful consideration for each pull request; Small and frequent pull request with complete unit function is welcomed.
Conform to Contributor Covenant Code of Conduct below.
If using IDEA, you can import the recommended Settings.
Through the uniform code style of spotless, execute the mvn spotless:apply formatted code.
Contributor Covenant Code of Conduct
Use linux line separators.
No meaningless blank lines. Please extract private methods to instead of blank lines if too long method body or different logic code fragments.
Use meaningful class, method and variable names, avoid to use abbreviate.
Return values are named with result; Variables in the loop structure are named with each; Replace each with entry in map.
Exceptions when catch are named with ex; Exceptions when catch but do nothing are named with ignored.
Name property files with Spinal Case(a variant of Snake Case which uses hyphens - to separate words).
Split codes that need to add notes with it into small methods, which are explained with method names.
Have constants on the left and variable on the right in = and equals conditional expressions; Have variable on the left and constants on the right in greater than and less than conditional expressions.
Beside using same names as input parameters and global fields in assign statement, avoid using this modifier.
Design class as final class except abstract class for extend.
Make nested loop structures a new method.
Order of members definition and parameters should be consistent during classes and methods.
Use guard clauses in priority.
Minimize the access permission for classes and methods.
Private method should be just next to the method in which it is used; Multiple private methods should be in the same as the appearance order of original methods.
No null parameters or return values.
Replace if else return and assign statement with ternary operator in priority.
Replace constructors, getters, setter methods and log variable with lombok in priority.
Use LinkedList in priority. Use ArrayList for use index to get element only.
Use capacity based Collection such as ArrayList, HashMap must indicate initial capacity to avoid recalculate capacity.
Use English in all the logs and javadoc.
Include Javadoc, todo and fixme only in the comments.
Only public classes and methods need javadoc, other methods, classes and override methods do not need javadoc.
conditional operator( ? : ) nested use is forbidden.
Contributor Covenant Unit Test of Conduct
Test codes and production codes should follow the same kind of code of conduct.
Unit test should follow AIR (Automatic, Independent, Repeatable) principle.
Automatic: Unit test should run automatically, not interactively. Check test result manually and System.out, log are prohibited, use assert to check test results.
Independent: Call each other and sequence dependency during unit test cases are prohibited. Every test case should run independent.
Repeatable: Unit test case should not dependency external environment, they can run repeatable.
Unit test should follow BCDE (Border, Correct, Design, Error) design principle.
Border: Border value test, test for loop border, special value and value sequence to get expect result.
Correct: Correct value test, test for correct value to get expect result.
Design: Design with production codes.
Error: Error value test, test for error input, exception to get expect result.
Without particular reasons, test cases should be fully covered.
Test cases should be fully covered expect simply getter /setter methods, and declared static codes of SPI, such as: getType / getOrder.
Every test case need precised assertion.
Environment preparation codes should be separate from test codes.
Only those that relate to junit Assert, hamcrest CoreMatchers and Mockito can use static import.
For single parameter asserts, assertTrue, assertFalse, assertNull and assertNotNull should be used.
For multiple parameter asserts, assertThat should be used.
For accurate asserts, try not to use not, containsString to make assertions.
Actual values of test cases should be named actualXXX, expected values expectedXXX.
Class for test case and @Test annotation do not need javadoc.
Contributor Covenant G4 Code of Conduct
Every line cannot over 200 chars, guarantee every line have complete semantics.
Every rule should be in single line, no empty line between rules.
Rule of lexer name should capitalization. If name composite with more than one word, use underline to separate. Rule name of DataType and Symbol should end with underline. If rule name is conflicted with ANTLR’s keyword, should take an underline behind rule name.
For private rule in lexer should use fragment, rule with fragment should define behind of public rule which they served.
Common rule of lexer should put in file Keyword.g4, every database may has customized rule file by themselves. For example: MySQLKeyword.g4.
After every rule finish, blank line should no indents.
No space before rule name definition. One space between colon and rule, semicolon should take a new line and keep indents (including blank lines) consistent with the previous one.
If a rule’s branch is over than 5, every branch take a new line.
Rule name of parser should same with java variable’s camel case.
Define separate files for every SQL type, file name should consist of database + SQL type + Statement. For example: MySQLDQLStatement.g4.