01-coupling

Coupling

For details, see Common Anti-Patterns in Go Web Applications.

Strong coupling makes your Web App hard to maintain over time.

The first example shows a tightly coupled service, and the following three a few tactics to approach loose coupling.

All examples cover the same domain and work in the same way.

Examples

1. Tightly Coupled
2. Loosely Coupled
3. Loosely Coupled with Code Generation
4. Loosely Coupled with Application Layer

Tests

The tests directory holds end-to-end tests for all examples. All applications work the same and expose the same API.

Running

The docker-compose definition holds all services and their dependencies. Run it with:

docker-compose up

Then, run end-to-end tests for all examples at once:

make test

Lines of code comparison

01-tightly-coupled

Language	files	blank	comment	code
Go	4	60	0	292
SQL	1	0	0	1
--------	--------	--------	--------	--------
SUM:	5	60	0	293

02-loosely-coupled

Language	files	blank	comment	code
Go	3	72	0	345
SQL	1	0	0	1
--------	--------	--------	--------	--------
SUM:	4	72	0	346

03-loosely-coupled-generated

Language	files	blank	comment	code
Go	11	549	175	2452
YAML	1	7	0	124
SQL	1	2	0	21
TOML	1	0	0	5
--------	--------	--------	--------	--------
SUM:	14	558	175	2602

04-loosely-coupled-app-layer

Language	files	blank	comment	code
Go	12	575	181	2562
YAML	1	7	0	124
SQL	1	2	0	21
TOML	1	0	0	5
--------	--------	--------	--------	--------
SUM:	15	584	181	2712