Add support for postgres citext data-type

[justinkalland]

Pull Request check-list

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• Does npm run test or npm run test-DIALECT pass with this change (including linting)?
• Does the description below contain a link to an existing issue (Closes #[issue]) or a description of the issue you are solving?
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Description of change

Adds support for CITEXT data-type. This is a Postgres only data-type. This also adds support for ARRAY(CITEXT).

To use CITEXT it must first be enabled in Postgres:

CREATE EXTENSION IF NOT EXISTS citext;

The new tests will fail unless the module is enabled in Postgres. I have created as change to enable the module in the custom Docker image: sushantdhiman/sequelize-postgres#1

Closes #9116
Closes #6572

[sushantdhiman]

Looks good. I have updated docker images for CI

[sushantdhiman]

No need for this in supports, these flags are meant to switch code segments when generating queries or declaring support information that is used anywhere in lib/, for tests you can just compare dialect === 'postgres'

[sushantdhiman]

As this implementation is not changed, defining function CITEXT is not required. You just need

  BaseTypes.CITEXT.types.postgres = {
    oids: [146932],
    array_oids: [146937]
  };

[sushantdhiman]

There is some issue with postgres-9.5 image, I'll fix that in evening (approx 7-8 hours). postgres-10 image is working properly so you can use that to verify your changes on CI

[codecov]

Codecov Report

Merging #10024 into master will decrease coverage by 0.02%.
The diff coverage is 82.35%.

@@            Coverage Diff             @@
##           master   #10024      +/-   ##
==========================================
- Coverage   96.38%   96.36%   -0.03%     
==========================================
  Files          63       63              
  Lines        9386     9399      +13     
==========================================
+ Hits         9047     9057      +10     
- Misses        339      342       +3

Impacted Files	Coverage Δ
lib/dialects/postgres/data-types.js	97.82% <100%> (ø)	⬆️
lib/dialects/postgres/connection-manager.js	93.63% <100%> (+0.11%)	⬆️
lib/data-types.js	95.21% <70%> (-0.54%)	⬇️

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[sushantdhiman]

Now all images has been fixed, please address my code related comments and this can be merged

[sushantdhiman]

Please add a standard datatypes test here

[sushantdhiman]

Sequelize.CITEXT not Sequelize.CITEXT()

[justinkalland]

Discovered that CITEXT has dynamic OIDs and changed to handle that.

[sushantdhiman]

dataTypes.postgres.CITEXT is not available, right?

As we need to dynamically update OIDs it is better to define this type in postgres/data-types.js

  function CITEXT(options) {
    if (!(this instanceof CITEXT)) return new CITEXT(options);
    BaseTypes.CITEXT.apply(this, arguments);
  }
  inherits(CITEXT, BaseTypes.CITEXT);

  BaseTypes.CITEXT.types.postgres = {
    oids: [],
    array_oids: []
  };

and have it exported. So you can use dataTypes.postgres.CITEXT here and in code just below

[justinkalland]

Perhaps it is bit much to redeclare in the Postgres data-types? If you are concerned about how it looks, this would be cleaner:

      // Reset OID mapping for dynamic type
      [
        dataTypes.GEOMETRY,
        dataTypes.HSTORE,
        dataTypes.GEOGRAPHY,
        dataTypes.ENUM,
        dataTypes.CITEXT
      ].forEach(type => {
        type.types.postgres.oids = [];
        type.types.postgres.array_oids = [];
      });

      for (const row of result.rows) {
        let type;

        if (row.typname === 'geometry') {
          type = dataTypes.GEOMETRY;
        } else if (row.typname === 'hstore') {
          type = dataTypes.HSTORE;
        } else if (row.typname === 'geography') {
          type = dataTypes.GEOGRAPHY;
        } else if (row.typname === 'citext') {
          type = dataTypes.CITEXT;
        } else if (row.typtype === 'e') {
          type = dataTypes.ENUM;
        }

[sushantdhiman]

Thanks @justinkalland