Mock truncate of go.work.sum to avoid removing it after tests

library.sh

@@ -774,7 +774,7 @@ function go_update_deps() {
 function __clean_goworksum_if_exists() {
   if [ -f "$REPO_ROOT_DIR/go.work.sum" ]; then
     log.step 'Cleaning the go.work.sum file'
-    true > "$REPO_ROOT_DIR/go.work.sum"
+    truncate --size 0 "$REPO_ROOT_DIR/go.work.sum"
   fi
 }
 

test/unit/presubmit_test.go

@@ -24,9 +24,9 @@ func TestPresubmitTestMainFunc(t *testing.T) {
 			contains("Build tests for knative.dev/hack/schema"),
 			contains("Build tests for knative.dev/hack"),
 			contains("Checking that go code builds"),
-			contains("go test -vet=off -tags e2e,library -exec echo ./..."),
-			contains("go test -vet=off -tags  -exec echo ./..."),
-			contains("go run knative.dev/test-infra/tools/kntest/cmd/kntest@latest" +
+			contains("👻 go test -vet=off -tags e2e,library -exec echo ./..."),
+			contains("👻 go test -vet=off -tags  -exec echo ./..."),
+			contains("👻 go run knative.dev/test-infra/tools/kntest/cmd/kntest@latest" +
 				" junit --suite=_build_tests --name=Check_Licenses --err-msg= --dest="),
 			header("BUILD TESTS PASSED"),
 		},

test/unit/update_deps_test.go

@@ -9,6 +9,10 @@ func TestUpdateDeps(t *testing.T) {
 	sc := newShellScript(
 		loadFile("source-library.bash"),
 		mockGo(),
+		mockBinary("truncate", response{
+			args:     startsWith{"--size 0"},
+			response: simply(""),
+		}),
 	)
 	tcs := []testCase{{
 		name:    "go_update_deps --unknown",
@@ -24,24 +28,26 @@ func TestUpdateDeps(t *testing.T) {
 			contains("Golang module: knative.dev/hack"),
 			contains("Checking licenses"),
 			contains("Removing unwanted vendor files"),
-			contains("go mod tidy"),
-			contains("go run github.com/google/go-licenses@v1.6.0 check"),
+			contains("👻 go mod tidy"),
+			contains("👻 go run github.com/google/go-licenses@v1.6.0 check"),
+			contains("👻 go mod download -x"),
 		},
 	}, {
 		name: "go_update_deps --upgrade",
 		stdout: []check{
-			contains("go run knative.dev/toolbox/buoy@latest float ./go.mod " +
-				"--release v9000.1 --domain knative.dev"),
+			contains("👻 go run knative.dev/toolbox/buoy@latest float " +
+				"./go.mod --release v9000.1 --domain knative.dev"),
 		},
 	}, {
 		name: "go_update_deps --upgrade --release 1.25 --module-release 0.28",
 		stdout: []check{
-			contains("go run knative.dev/toolbox/buoy@latest float ./go.mod " +
-				"--release 1.25 --domain knative.dev --module-release 0.28"),
+			contains("👻 go run knative.dev/toolbox/buoy@latest float " +
+				"./go.mod --release 1.25 --domain knative.dev " +
+				"--module-release 0.28"),
 		},
 	}}
-	for _, tc := range tcs {
-		tc := tc
+	for i := range tcs {
+		tc := tcs[i]
 		t.Run(tc.name, tc.test(sc))
 	}
 }