Make Travis CI builds pass for all supported branches

[SergeyBiryukov]

Previously:

#40106

Test the 3.7 branch on Travis

#40463

Get the tests for the 4.0 branch passing

#46646

Fix Travis CI builds for the 4.0 branch

Background:

#26042

wp_save_post_revision() can compare against the wrong $last_revision post

#28706

Lots of Multisite tests are exploding

#30284

Remove failing automated tests from the suite

#31091

A number of external-http requests are failing due to HTTPS redirects

#35105

Specifiy minimum node and npm version in package.json

#39486

In Travis, skip some tests when not on trunk

#40086

Get Travis tests working again on PHP 7

Since we're still backporting security fixes all the way back to 3.7 for the time being, it would be helpful to get the tests running on these older branches, so that we could be more confident in patch releases.

By backporting some changes from the 4.0 branch, we can make the tests pass on 3.9 and older branches.

[SergeyBiryukov]

In 47329:

Build/Test Tools: Fix the Travis CI build for the 3.9 branch.

Among other fixes, this backports [28943], [28961], [28964-28968], [28988], [29120], [29251], [29503], [29860], [29869], [29954], [30001], [30160], [30282], [30285], [30289-30291], [30513-30514], [30516-30521], [30523-30524], [30526], [30529-30530], [31253-31254], [31257-31259], [31622], [33374], [40255], [40257], [40259], [40269], [40271], [40446], [40449], [40457], [40604], [40538], [40833], [41082], [41303], [41306], [44993].

See #49485.

[SergeyBiryukov]

In 47331:

Build/Test Tools: Merge some test fixes to the 4.0 branch, for consistency with other branches.

This backports [30518], [30520], [30526], [31253-31254], [31257].

See #49485.

[SergeyBiryukov]

In 47332:

Build/Test Tools: Merge some test fixes to the 4.1 branch, for consistency with other branches.

This backports [31253-31254], [31257].

See #49485.

[SergeyBiryukov]

In 47333:

Build/Test Tools: Improve Travis CI configuration for better performance on 3.9 branch.

This backports [28799] and [28873].

See #49485.

[SergeyBiryukov]

In 47334:

Posts, Post Types: Ensure edit_post() promotes an auto-draft to draft.

This fixes a regression in 3.8 branch introduced in [44074].

Follow-up to [28073].

See #49485.

[SergeyBiryukov]

In 47335:

Posts, Post Types: Ensure edit_post() promotes an auto-draft to draft.

This fixes a regression in 3.7 branch introduced in [44076].

Follow-up to [28073].

Merges [47334] to the 3.7 branch.
See #49485.

[SergeyBiryukov]

In 47336:

Build/Test Tools: Display PHPUnit information for PHP tests only (for 5.2 branch).

This avoids a build error on travis:format job, caused by Travis running PHPUnit 9.x by default, which requires PHP 7.3+.

See #49485.

[SergeyBiryukov]

In 47337:

Build/Test Tools: Display PHPUnit information for PHP tests only (for 5.1 branch).

This avoids a build error on travis:format job, caused by Travis running PHPUnit 9.x by default, which requires PHP 7.3+.

Merges [47336] to the 5.1 branch.
See #49485.

[SergeyBiryukov]

In 47338:

Build/Test Tools: Fix the Travis CI build for the 3.8 branch.

Among other fixes, this backports [26871], [26909-26910], [26940], [27086], [27168], [28799], [28873], [28943], [28961], [28964], [28966-28967], [29120], [29251], [29503], [29860], [29869], [29954], [30001], [30160], [30282], [30285], [30289-30291], [30513-30514], [30516-30521], [30524], [30526], [30529-30530], [31253-31254], [31257-31259], [31622], [40241], [40255], [40257], [40259], [40269], [40271], [40446], [40449], [40457], [40604], [40538], [40833], [41082], [41303], [41306], [44993].

See #49485.

[SergeyBiryukov]

In 47341:

Build/Test Tools: Remove unused ::assertPostHasTerms() method from tests/term.php.

The associated test was removed in [30241].

See #49485.

[SergeyBiryukov]

In 47343:

Build/Test Tools: Fix the Travis CI build for the 3.7 branch.

Among other fixes, this backports [26087], [26091], [26095], [26252], [26307], [26318], [26512], [26705], [26871], [26909-26910], [26940], [27086], [27168], [28799], [28873], [28943], [28961], [28964], [28966-28967], [29120], [29251], [29503], [29860], [29869], [29954], [30001], [30282], [30285], [30289-30291], [30513-30514], [30516-30521], [30524], [30526], [30529-30530], [31253-31254], [31257-31259], [31622], [40241], [40255], [40257], [40259], [40269], [40271], [40446], [40449], [40457], [40604], [40538], [40833], [41082], [41303], [41306], [44993].

See #49485.

[SergeyBiryukov]

3.9: ​https://travis-ci.com/WordPress/wordpress-develop/builds/149874621
3.8: ​https://travis-ci.com/WordPress/wordpress-develop/builds/150011961
3.7: ​https://travis-ci.com/WordPress/wordpress-develop/builds/150144281

[SergeyBiryukov]

#40106 was marked as a duplicate.

[SergeyBiryukov]

In 47489:

Build/Test Tools: Remove unused ::assertPostHasTerms() method from tests/term.php.

The associated test was removed in [30241].

Merges [47341] to 3.7+ branches.
See #49485.

[SergeyBiryukov]

In 47490:

When asserting microtime output as a number, make it a number.

microtime is by default a string. Doing a greater then or less than check of that string is a bad idea since it uses the first part (the micro part of microtime) rather then the actual time. This adds a helper to convert microtime output into a float which we can then use to properly compare the output of microtime.

This fixes an intermittent test failure.

Props jorbin.
Merges [30337] to the 3.9 branch.
See #30336, #49485.

[SergeyBiryukov]

In 47491:

When asserting microtime output as a number, make it a number.

microtime is by default a string. Doing a greater then or less than check of that string is a bad idea since it uses the first part (the micro part of microtime) rather then the actual time. This adds a helper to convert microtime output into a float which we can then use to properly compare the output of microtime.

This fixes an intermittent test failure.

Props jorbin.
Merges [30337] to the 3.8 branch.
See #30336, #49485.

[SergeyBiryukov]

In 47492:

When asserting microtime output as a number, make it a number.

microtime is by default a string. Doing a greater then or less than check of that string is a bad idea since it uses the first part (the micro part of microtime) rather then the actual time. This adds a helper to convert microtime output into a float which we can then use to properly compare the output of microtime.

This fixes an intermittent test failure.

Props jorbin.
Merges [30337] to the 3.7 branch.
See #30336, #49485.