FoBiS.py

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4. Before releasing ​

A change to core is safe only if mathx and app still build and pass their tests with it. check tries exactly that, before anything is committed or released: it copies each dependent into a scratch directory, puts core's working copy in place of the fetched one, and runs the dependent's checks (its fobos [ecosystem] check commands; the demo's build and run the test program).

console
$ fobis ecosystem check core
Checking mathx, app against the local working copy of core

==> mathx: (fobis build --quiet) && (./build/test_mathx)

Building src/test_mathx.f90
Compiling third_party/core/src/core_m.f90 serially
Compiling src/mathx_m.f90 serially
Compiling src/test_mathx.f90 serially
Linking build/test_mathx
Target src/test_mathx.f90 has been successfully built
mathx: all tests passed

==> app: (fobis build --quiet) && (./build/app)

Building src/app.f90
Compiling third_party/core/src/core_m.f90 serially
Compiling third_party/mathx/src/mathx_m.f90 serially
Compiling src/app.f90 serially
Linking build/app
Target src/app.f90 has been successfully built
twice(3) =  6.0   quadruple(3) = 12.0

Project  Result        Time  Detail
mathx    passed        0.2s
app      passed        0.3s

2 passed, 0 failed

Now a change that breaks the others: twice renamed double in core, not committed.

console
$ git -C core diff --stat
 src/core_m.f90    | 6 +++---
 src/test_core.f90 | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

What the change breaks ​

impact compares the public interface of core's modules with the last release, and finds the code of the dependents that uses what changed, without building anything:

console
$ fobis ecosystem impact core
core: public API changes since v1.0.0
           added   procedure core_m::double (src/core_m.f90:6)
           added   procedure core_m::halve (src/core_m.f90:12)
  BREAKING removed procedure core_m::twice (src/core_m.f90:6)

mathx: affected
  src/mathx_m.f90:2: use core_m, only: twice  [changed: twice]
    src/mathx_m.f90:10: twice: y = twice(twice(x))
app: affected
  src/app.f90:2: use core_m, only: twice  [changed: twice]
    src/app.f90:5: twice: print '(A,F5.1,A,F5.1)', "twice(3) =", twice(3.0), " quadruple(3) =", quadruple(3.0)

1 breaking change(s); 2 of 2 dependent project(s) affected.
[exit status 1]
  • A removed or changed public entity is a breaking change; an added one is not.
  • A dependent is affected only when its code refers to a changed name (a plain use of the module is not enough).

Proof by building ​

console
$ fobis ecosystem check core
Checking mathx, app against the local working copy of core

==> mathx: (fobis build --quiet) && (./build/test_mathx)

Building src/test_mathx.f90
Compiling third_party/core/src/core_m.f90 serially
Compiling src/mathx_m.f90 serially
src/mathx_m.f90:2:19:

    2 |   use core_m, only: twice
      |                   1
Error: Symbol 'twice' referenced at (1) not found in module 'core_m'
src/mathx_m.f90:10:14:

   10 |     y = twice(twice(x))
      |              1
Error: Function 'twice' at (1) has no IMPLICIT type
src/mathx_m.f90:10:14:

   10 |     y = twice(twice(x))
      |              1
Error: Reference to impure function 'twice' at (1) within a PURE procedure


==> app: (fobis build --quiet) && (./build/app)

Building src/app.f90
Compiling third_party/core/src/core_m.f90 serially
Compiling third_party/mathx/src/mathx_m.f90 serially
third_party/mathx/src/mathx_m.f90:2:19:

    2 |   use core_m, only: twice
      |                   1
Error: Symbol 'twice' referenced at (1) not found in module 'core_m'
third_party/mathx/src/mathx_m.f90:10:14:

   10 |     y = twice(twice(x))
      |              1
Error: Function 'twice' at (1) has no IMPLICIT type
third_party/mathx/src/mathx_m.f90:10:14:

   10 |     y = twice(twice(x))
      |              1
Error: Reference to impure function 'twice' at (1) within a PURE procedure


Staged copies kept in ~/tmp/fobis-check-core-lsrgeosw

Project  Result        Time  Detail
mathx    failed        0.2s  exit 1
app      failed        0.2s  exit 1

0 passed, 2 failed: mathx, app
[exit status 1]

The staged copies are kept when a check fails, to look at; the projects themselves were not touched.

fobis ecosystem check

The demo ecosystem of this track: core, mathx, app.

What you learned

fobis ecosystem check PROJECT (dependents built against your working copy) and fobis ecosystem impact PROJECT (which public names changed, and who uses them).

Next: 5. Shared boilerplate.