GEMINI.md

1# Impeller
2 
3This directory contains Flutter's graphics renderer, Impeller.
4 
5## Development operations
6 
7### Unit testing
8 
9Running all unit tests can take over 10 minutes. It's best to run a subset of
10tests while developing, then verify all tests at the end.
11 
12#### Building and running unit-tests
13 
14```shell
15../bin/et build -c host_debug_unopt_arm64 \
16  //flutter/impeller:impeller_unittests
17../../out/host_debug_unopt_arm64/impeller_unittests
18```
19 
20#### Running a specific unit test
21 
22```shell
23../../out/host_debug_unopt_arm64/impeller_unittests \
24  --gtest_filter="SizeTest.SizeIsEmpty"
25```
26 
27#### List unit-tests
28 
29```shell
30../../out/host_debug_unopt_arm64/impeller_unittests --gtest_list_tests
31```
32 
33### Golden testing
34 
35The executable for golden testing is `impeller_golden_tests`.  The CWD must be
36the parent directory of `impeller_golden_tests` when executing it in order for
37the dyld to resolve successfully.
38 
39The golden tests are currently only supported on macOS.
40 
41#### Build/run/examine golden test
42 
43This example assumes macOS with an arm64 processor.
44 
45```shell
46../bin/et build -c host_debug_unopt_arm64 \
47  //flutter/impeller/golden_tests:impeller_golden_tests
48mkdir -p ~/Desktop/impeller_unit_tests
49pushd $PWD
50cd ../../out/host_debug_unopt_arm64
51./impeller_golden_tests \
52  --working_dir=~/Desktop/impeller_unit_tests \
53  --gtest_filter="Play/AiksTest.CanPerformSkew/Metal"
54popd
55open ~/Desktop/impeller_unit_tests/impeller_Play_AiksTest_CanPerformSkew_Metal.png
56```
57 
58#### List golden tests
59 
60```shell
61pushd $PWD
62cd ../../out/host_debug_unopt_arm64
63./impeller_golden_tests --working_dir=. --gtest_list_tests
64popd
65```
66