Improve build/feedback times

[rngadam]

During development, we want <2s change->test change loops.

setup:

OS X Yosemite 10.10.5
2.4 GHz Intel Core i5
8G memory
Meteor 1.4.1.1

https://gist.github.com/rngadam/84f8dbebe88efd5bf84c4a25e00f0de0

| (#1) Total: 4,491 ms (ProjectContext prepareProjectForBuild)
| (#2) Total: 16,249 ms (Build App)

worse offenders:

| Top leaves:
| meteorNpm.runNpmCommand..................................1,559 ms (1)
| ImportScanner#_findImportedModuleIdentifiers.............1,360 ms (683)
| files.readdir............................................1,254 ms (158)
| files.readFile...........................................1,106 ms (1260)

Explore:

• hot module replacement https://github.com/gadicc/meteor-hmr
• remove dependencies https://gist.github.com/rngadam/599a293df2246230b51a6479172f08e6
• aggressive modular construction
• build on memory disk? different file system?
• measure on Ubuntu 16.04
• parallel reading?
• reduce dependency redundancies (minor versions differences)

[rngadam]

https://gist.github.com/rngadam/599a293df2246230b51a6479172f08e6

dependency tree as these leaf specs:

  [email protected]
  [email protected] || 1.0.1
  [email protected] || 1.0.1 || 1.0.1
  [email protected]
  [email protected] || 1.0.1
  [email protected]
  [email protected]
  [email protected]
  [email protected]
  [email protected]
  [email protected]
  [email protected]

but only 1.0.9 in ~/.meteor/packages/underscore

[rngadam]

One load in an incognito window (not logged in):

...same weight as if logged in which shows there's no code splitting.

[rngadam]

with all code moved to imports/

https://gist.github.com/rngadam/f52f6e8befce1368719cca875229da34

[rngadam]

still amazing amount of code loaded from the dependencies: