Improve string tests in FppTest

[karan9617]

Fixes #3703
#3703

Reason for Change

1. NonPrimitiveTest.ToString unit test was failing due to Fw::String buffer capacity limits truncating the formatted struct output during assertion checks.
2. Clang compiler threw -Werror variadic macro warnings on INSTANTIATE_TYPED_TEST_SUITE_P in PrimitiveTest.cpp and main.cpp.

Description of Changes

• Updated NonPrimitiveTest.cpp to use Fw::StringTemplate<1024> buffer capacity to hold complete string representations without truncation during toString() assertions.
• Adjusted final whitespace formatting string in NonPrimitiveTest.ToString to match actual operator output.
• Added trailing commas to INSTANTIATE_TYPED_TEST_SUITE_P instantiations in PrimitiveTest.cpp and main.cpp for standard C++ variadic macro compliance under strict compiler flags.

Build/Test Status

• Ran unit tests locally: ninja FppTest_struct_ut_exe && ./bin/Darwin/FppTest_struct_ut_exe
• Result: 38/38 PASSED across all 7 test suites with 0 gcov/coverage warnings.

[LeStarch]

@Kronos3 does this fix your issues? @bocchino ?

[github-actions]

Coverage report — base devel

Overall (line): 83.66% → 83.66% (+0.00)
Regression threshold: 0.50% (line).

Regressions

(none over threshold)

Modules changed

Module	Line	Δ	Function	Δ	Branch	Δ
Svc/FpySequencer	86.31	-0.03	98.59	+0.00	77.18	+0.00
Svc/CmdDispatcher	97.00	+0.03	91.67	+0.00	91.49	-0.09
Os/Generic	89.25	+0.13	88.16	+0.00	73.27	+0.00
Fw/DataStructures	98.22	+0.44	97.14	+0.00	82.97	+0.74
Os/Generic/Types	92.50	+0.71	92.86	+0.00	76.64	+1.87

Modules without UTs

CFDP/Checksum/GTest, Drv/LinuxGpioDriver, Drv/LinuxI2cDriver, Drv/LinuxSpiDriver, Drv/LinuxUartDriver, Drv/Ports/DataTypes, FppTestProject/FppTest/topology/async, FppTestProject/FppTest/topology/components/Comp, FppTestProject/FppTest/topology/components/Framework, FppTestProject/FppTest/topology/components/Receiver, FppTestProject/FppTest/topology/components/Sender, FppTestProject/FppTest/topology/guarded, FppTestProject/FppTest/topology/sync, FppTestProject/FppTest/topology/top_ports, FppTestProject/FppTest/topology/types, Fw/Com, Fw/Comp, Fw/FilePacket/GTest, Fw/Fpy, Fw/Obj, Fw/Port, Fw/Prm, Fw/Sm, Fw/Test, Fw/Types/GTest, Os/Models, Svc/Ccsds/Types, Svc/FatalHandler, Svc/Subtopologies/CdhCore, Svc/Subtopologies/ComCcsds, Svc/Subtopologies/ComCcsdsSdls, Svc/Subtopologies/ComFprime, Svc/Subtopologies/ComLoggerTee, Svc/Subtopologies/DataProducts, Svc/Subtopologies/DpCompression, Svc/Subtopologies/FileHandling, Svc/Subtopologies/FileHandlingCfdp, Svc/Subtopologies/FileHandlingCfdp/FileHandlingCfdpConfig, TestDeploymentsProject/Ref/DpDemo, TestDeploymentsProject/Ref/PingReceiver, TestDeploymentsProject/Ref/RecvBuffApp, TestDeploymentsProject/Ref/SendBuffApp, TestDeploymentsProject/Ref/Top, TestDeploymentsProject/Ref/TypeDemo, cmake/test/data/TestConfigDeployment, cmake/test/data/TestDeployment/TestBuildAutocoder, cmake/test/data/TestDeployment/TestHeaderAutocoder, cmake/test/data/TestDeployment/TestLinkDepends, cmake/test/data/TestDeployment/TestRelative, cmake/test/data/test-fprime-library/TestLibrary/TestComponent, cmake/test/data/test-fprime-library2/TestLibrary2/TestComponent

[Kronos3]

The preferred fix would be to get nasa/fpp#968 up to date and not rely on serializing to a string before sending to ostream

[bocchino]

This is better for testing s.toString, but now it doesn't test the << method of s at all. Can we keep both tests here (the truncated and non-truncated versions)?

[karan9617]

Updated the test to explicitly verify both the truncated operator<< behavior and the non-truncated toString() output using the larger buffer

[bocchino]

Looks good! Can you apply the same change to PrimitiveTest? The two cases (PrimitiveTest, NonPrimitiveTest) should operate in the same way.

[karan9617]

Done! I've updated PrimitiveTest to follow the exact same two-case testing pattern, verifying both the truncated operator<< output and the full toString() output.

[bocchino]

Looks good!