ci: avoid collecting coverage data on local dev (lambdaclass#1519)

Add the `TEST_COLLECT_COVERAGE` environmental variable to the `Makefile`
and use it to determine whether to use `llvm-cov` when running tests via
the `make` target.
Set it for CI so the pipelines still collect it. This should both make
local dev faster and save our disk space.

Co-authored-by: fmoletta <[email protected]>

.github/workflows/rust.yml

@@ -18,6 +18,7 @@ env:
     cairo_programs/**/*.json
     !cairo_programs/manually_compiled/*
     examples/wasm-demo/src/array_sum.json
+  TEST_COLLECT_COVERAGE: 1
   PROPTEST_CASES: 100
 
 jobs:

Makefile

@@ -238,15 +238,20 @@ cairo-vm_proof_trace: $(CAIRO_RS_TRACE_PROOF) $(CAIRO_RS_MEM_PROOF) $(CAIRO_RS_A
 cairo_trace: $(CAIRO_TRACE) $(CAIRO_MEM)
 cairo-vm_trace: $(CAIRO_RS_TRACE) $(CAIRO_RS_MEM)
 
+TEST_COMMAND:=cargo nextest run
+ifdef TEST_COLLECT_COVERAGE
+	TEST_COMMAND:=cargo llvm-cov nextest --no-report
+endif
+
 test: cairo_proof_programs cairo_test_programs cairo_1_test_contracts cairo_2_test_contracts
-	cargo llvm-cov nextest --no-report --workspace --features "test_utils, cairo-1-hints"
+	$(TEST_COMMAND) --workspace --features "test_utils, cairo-1-hints"
 test-no_std: cairo_proof_programs cairo_test_programs
-	cargo llvm-cov nextest --no-report --workspace --features test_utils --no-default-features
+	$(TEST_COMMAND) --workspace --features test_utils --no-default-features
 test-wasm: cairo_proof_programs cairo_test_programs
 	# NOTE: release mode is needed to avoid "too many locals" error
 	wasm-pack test --release --node vm --no-default-features
 test-extensive_hints: cairo_proof_programs cairo_test_programs
-	cargo llvm-cov nextest --no-report --workspace --features "test_utils, cairo-1-hints, extensive_hints"
+	$(TEST_COMMAND) --workspace --features "test_utils, cairo-1-hints, extensive_hints"
 
 check-fmt:
 	cargo fmt --all -- --check