tools/src/cmd/fuzz/experiment_test.go - dawn.git - Git at Google

 // Copyright 2026 The Dawn & Tint Authors
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are met:
 //
 //  1. Redistributions of source code must retain the above copyright notice, this
 //     list of conditions and the following disclaimer.
 //
 //  2. Redistributions in binary form must reproduce the above copyright notice,
 //     this list of conditions and the following disclaimer in the documentation
 //     and/or other materials provided with the distribution.
 //
 //  3. Neither the name of the copyright holder nor the names of its
 //     contributors may be used to endorse or promote products derived from
 //     this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 package main

 import (
 	"path/filepath"
 	"testing"

 	"dawn.googlesource.com/dawn/tools/src/execwrapper"
 	"dawn.googlesource.com/dawn/tools/src/oswrapper"
 	"github.com/stretchr/testify/require"
 )

 func TestCheckGnArgs(t *testing.T) {
 	tests := []struct {
 		name    string
 		gnJson  string
 		fuzzers []string
 		wantErr bool
 	}{
 		{
 			name: "Correct baseline flags",
 			gnJson: `[
 				{"name": "use_libfuzzer", "current": {"value": "true"}},
 				{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
 				{"name": "use_clang_coverage", "current": {"value": "true"}},
 				{"name": "optimize_for_fuzzing", "current": {"value": "false"}}
 			]`,
 			fuzzers: []string{"tint_wgsl_fuzzer"},
 			wantErr: false,
 		},
 		{
 			name: "Missing use_clang_coverage",
 			gnJson: `[
 				{"name": "use_libfuzzer", "current": {"value": "true"}},
 				{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
 				{"name": "optimize_for_fuzzing", "current": {"value": "false"}}
 			]`,
 			fuzzers: []string{"tint_wgsl_fuzzer"},
 			wantErr: true,
 		},
 		{
 			name: "optimize_for_fuzzing is true",
 			gnJson: `[
 				{"name": "use_libfuzzer", "current": {"value": "true"}},
 				{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
 				{"name": "use_clang_coverage", "current": {"value": "true"}},
 				{"name": "optimize_for_fuzzing", "current": {"value": "true"}}
 			]`,
 			fuzzers: []string{"tint_wgsl_fuzzer"},
 			wantErr: true,
 		},
 		{
 			name: "Correct IR flags",
 			gnJson: `[
 				{"name": "use_libfuzzer", "current": {"value": "true"}},
 				{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
 				{"name": "use_clang_coverage", "current": {"value": "true"}},
 				{"name": "optimize_for_fuzzing", "current": {"value": "false"}},
 				{"name": "tint_build_ir_binary", "current": {"value": "true"}},
 				{"name": "tint_has_protobuf", "current": {"value": "true"}}
 			]`,
 			fuzzers: []string{"tint_ir_fuzzer"},
 			wantErr: false,
 		},
 		{
 			name: "Missing IR protobuf flag",
 			gnJson: `[
 				{"name": "use_libfuzzer", "current": {"value": "true"}},
 				{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
 				{"name": "use_clang_coverage", "current": {"value": "true"}},
 				{"name": "optimize_for_fuzzing", "current": {"value": "false"}},
 				{"name": "tint_build_ir_binary", "current": {"value": "true"}}
 			]`,
 			fuzzers: []string{"tint_ir_fuzzer"},
 			wantErr: true,
 		},
 	}

 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			fs := oswrapper.CreateFSTestOSWrapper()
 			ew := execwrapper.NewTestExecWrapperForSuccess([]byte(tc.gnJson), nil)

 			cfg := &taskConfig{
 				mainConfig: mainConfig{
 					build:       "/build",
 					osWrapper:   fs,
 					execWrapper: ew,
 				},
 			}

 			_, err := checkGnArgs(cfg, tc.fuzzers)
 			if tc.wantErr {
 				require.Error(t, err)
 			} else {
 				require.NoError(t, err)
 			}
 		})
 	}
 }

 func TestGenerateTasksForFuzzer(t *testing.T) {
 	secs := 3600
 	runs := 100000
 	customIters := 2

 	corpus := CorpusDef{Name: "tint_tests", Path: "tint_tests_dir"}

 	settings := &ExperimentSettings{
 		DefaultIterations: 5,
 		Durations: []DurationDef{
 			{Seconds: &secs},
 			{Runs: &runs, Iterations: &customIters},
 		},
 	}

 	tasks, err := calculateTasksForFuzzer("tint_wgsl_fuzzer", corpus, "/root/corpora", "/root/results/default", settings)

 	require.NoError(t, err)
 	require.Len(t, tasks, 7)

 	require.Equal(t, "tint_wgsl_fuzzer", tasks[0].FuzzerName)
 	require.Equal(t, "tint_tests", tasks[0].CorpusName)
 	require.Equal(t, filepath.Join("/root/corpora", "tint_tests_dir"), tasks[0].CorpusPath)
 	require.Equal(t, ExperimentLimitTypeSeconds, tasks[0].LimitType)
 	require.Equal(t, 3600, tasks[0].LimitValue)
 	require.Equal(t, 1, tasks[0].Iteration)
 	require.Equal(t, filepath.Join("/root/results/default", "tint_wgsl_fuzzer", "tint_tests", "seconds_3600", "iter_1"), tasks[0].TaskDir)

 	lastIdx := len(tasks) - 1
 	require.Equal(t, ExperimentLimitTypeRuns, tasks[lastIdx].LimitType)
 	require.Equal(t, 100000, tasks[lastIdx].LimitValue)
 	require.Equal(t, 2, tasks[lastIdx].Iteration)
 	require.Equal(t, filepath.Join("/root/results/default", "tint_wgsl_fuzzer", "tint_tests", "runs_100000", "iter_2"), tasks[lastIdx].TaskDir)
 }

 func TestLoadExperimentSettings(t *testing.T) {
 	tests := []struct {
 		name        string
 		setupFS     func(fs oswrapper.FSTestOSWrapper)
 		wantErr     bool
 		errContains string
 		validate    func(t *testing.T, settings ExperimentSettings)
 	}{
 		{
 			name: "Valid experiment config",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10},
 						{"runs": 1000}
 					]
 				}`), 0644)
 			},
 			wantErr: false,
 			validate: func(t *testing.T, settings ExperimentSettings) {
 				require.Nil(t, settings.BenchmarkDuration)
 			},
 		},
 		{
 			name: "Valid experiment config with benchmark duration",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10},
 						{"runs": 1000}
 					],
 					"benchmark_duration": 45
 				}`), 0644)
 			},
 			wantErr: false,
 			validate: func(t *testing.T, settings ExperimentSettings) {
 				require.NotNil(t, settings.BenchmarkDuration)
 				require.Equal(t, 45, *settings.BenchmarkDuration)
 			},
 		},
 		{
 			name: "Valid experiment config with burn-in duration and enabled",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					],
 					"burnin_duration": 120,
 					"burnin_enabled": false
 				}`), 0644)
 			},
 			wantErr: false,
 			validate: func(t *testing.T, config ExperimentSettings) {
 				require.NotNil(t, config.BurnInDuration)
 				require.Equal(t, 120, *config.BurnInDuration)
 				require.NotNil(t, config.BurnInEnabled)
 				require.False(t, *config.BurnInEnabled)
 			},
 		},
 		{
 			name: "Invalid experiment config (both limit types set)",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10, "runs": 1000}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "has both 'seconds' and 'runs' defined",
 		},
 		{
 			name: "Invalid experiment config (neither limit type set)",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"iterations": 5}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "must define either 'seconds' or 'runs'",
 		},
 		{
 			name: "Missing config file",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 			},
 			wantErr:     true,
 			errContains: "experiment configuration file '/root/experiment.json' not found",
 		},
 		{
 			name: "No fuzzers specified",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": [],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "no fuzzers specified in 'fuzzers' list",
 		},
 		{
 			name: "Unsupported fuzzer",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["invalid_fuzzer_name"],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "unsupported fuzzer 'invalid_fuzzer_name'",
 		},
 		{
 			name: "Missing WGSL benchmark corpus",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "wgsl_benchmark_corpus is required in experiment.json because WGSL fuzzers are specified",
 		},
 		{
 			name: "Missing WGSL corpora",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "at least one wgsl_corpora definition is required in experiment.json because WGSL fuzzers are specified",
 		},
 		{
 			name: "WGSL benchmark corpus directory missing",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "wgsl benchmark corpus directory 'bench' not found under corpora root",
 		},
 		{
 			name: "WGSL corpus directory missing",
 			setupFS: func(fs oswrapper.FSTestOSWrapper) {
 				_ = fs.MkdirAll("/root/corpora/bench", 0755)
 				_ = fs.WriteFile("/root/experiment.json", []byte(`{
 					"name": "test_exp",
 					"hash": "abcdef",
 					"fuzzers": ["tint_wgsl_fuzzer"],
 					"wgsl_benchmark_corpus": "bench",
 					"wgsl_corpora": [
 						{"name": "corp1", "path": "test_corp"}
 					],
 					"default_iterations": 2,
 					"durations": [
 						{"seconds": 10}
 					]
 				}`), 0644)
 			},
 			wantErr:     true,
 			errContains: "wgsl corpus directory 'test_corp' not found under corpora root",
 		},
 	}

 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
 			fs := oswrapper.CreateFSTestOSWrapper()
 			tc.setupFS(fs)

 			cfg := &taskConfig{
 				mainConfig: mainConfig{
 					osWrapper: fs,
 				},
 			}

 			settings, err := loadExperimentSettings(cfg, "/root")
 			if tc.wantErr {
 				require.Error(t, err)
 				require.Contains(t, err.Error(), tc.errContains)
 			} else {
 				require.NoError(t, err)
 				require.Equal(t, "test_exp", settings.Name)
 				if tc.validate != nil {
 					tc.validate(t, settings)
 				}
 			}
 		})
 	}
 }
	// Copyright 2026 The Dawn & Tint Authors
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// 1. Redistributions of source code must retain the above copyright notice, this
	// list of conditions and the following disclaimer.
	//
	// 2. Redistributions in binary form must reproduce the above copyright notice,
	// this list of conditions and the following disclaimer in the documentation
	// and/or other materials provided with the distribution.
	//
	// 3. Neither the name of the copyright holder nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
	// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	package main

	import (
	"path/filepath"
	"testing"

	"dawn.googlesource.com/dawn/tools/src/execwrapper"
	"dawn.googlesource.com/dawn/tools/src/oswrapper"
	"github.com/stretchr/testify/require"
	)

	func TestCheckGnArgs(t *testing.T) {
	tests := []struct {
	name string
	gnJson string
	fuzzers []string
	wantErr bool
	}{
	{
	name: "Correct baseline flags",
	gnJson: `[
	{"name": "use_libfuzzer", "current": {"value": "true"}},
	{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
	{"name": "use_clang_coverage", "current": {"value": "true"}},
	{"name": "optimize_for_fuzzing", "current": {"value": "false"}}
	]`,
	fuzzers: []string{"tint_wgsl_fuzzer"},
	wantErr: false,
	},
	{
	name: "Missing use_clang_coverage",
	gnJson: `[
	{"name": "use_libfuzzer", "current": {"value": "true"}},
	{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
	{"name": "optimize_for_fuzzing", "current": {"value": "false"}}
	]`,
	fuzzers: []string{"tint_wgsl_fuzzer"},
	wantErr: true,
	},
	{
	name: "optimize_for_fuzzing is true",
	gnJson: `[
	{"name": "use_libfuzzer", "current": {"value": "true"}},
	{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
	{"name": "use_clang_coverage", "current": {"value": "true"}},
	{"name": "optimize_for_fuzzing", "current": {"value": "true"}}
	]`,
	fuzzers: []string{"tint_wgsl_fuzzer"},
	wantErr: true,
	},
	{
	name: "Correct IR flags",
	gnJson: `[
	{"name": "use_libfuzzer", "current": {"value": "true"}},
	{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
	{"name": "use_clang_coverage", "current": {"value": "true"}},
	{"name": "optimize_for_fuzzing", "current": {"value": "false"}},
	{"name": "tint_build_ir_binary", "current": {"value": "true"}},
	{"name": "tint_has_protobuf", "current": {"value": "true"}}
	]`,
	fuzzers: []string{"tint_ir_fuzzer"},
	wantErr: false,
	},
	{
	name: "Missing IR protobuf flag",
	gnJson: `[
	{"name": "use_libfuzzer", "current": {"value": "true"}},
	{"name": "tint_build_wgsl_reader", "current": {"value": "true"}},
	{"name": "use_clang_coverage", "current": {"value": "true"}},
	{"name": "optimize_for_fuzzing", "current": {"value": "false"}},
	{"name": "tint_build_ir_binary", "current": {"value": "true"}}
	]`,
	fuzzers: []string{"tint_ir_fuzzer"},
	wantErr: true,
	},
	}

	for _, tc := range tests {
	t.Run(tc.name, func(t *testing.T) {
	fs := oswrapper.CreateFSTestOSWrapper()
	ew := execwrapper.NewTestExecWrapperForSuccess([]byte(tc.gnJson), nil)

	cfg := &taskConfig{
	mainConfig: mainConfig{
	build: "/build",
	osWrapper: fs,
	execWrapper: ew,
	},
	}

	_, err := checkGnArgs(cfg, tc.fuzzers)
	if tc.wantErr {
	require.Error(t, err)
	} else {
	require.NoError(t, err)
	}
	})
	}
	}

	func TestGenerateTasksForFuzzer(t *testing.T) {
	secs := 3600
	runs := 100000
	customIters := 2

	corpus := CorpusDef{Name: "tint_tests", Path: "tint_tests_dir"}

	settings := &ExperimentSettings{
	DefaultIterations: 5,
	Durations: []DurationDef{
	{Seconds: &secs},
	{Runs: &runs, Iterations: &customIters},
	},
	}

	tasks, err := calculateTasksForFuzzer("tint_wgsl_fuzzer", corpus, "/root/corpora", "/root/results/default", settings)

	require.NoError(t, err)
	require.Len(t, tasks, 7)

	require.Equal(t, "tint_wgsl_fuzzer", tasks[0].FuzzerName)
	require.Equal(t, "tint_tests", tasks[0].CorpusName)
	require.Equal(t, filepath.Join("/root/corpora", "tint_tests_dir"), tasks[0].CorpusPath)
	require.Equal(t, ExperimentLimitTypeSeconds, tasks[0].LimitType)
	require.Equal(t, 3600, tasks[0].LimitValue)
	require.Equal(t, 1, tasks[0].Iteration)
	require.Equal(t, filepath.Join("/root/results/default", "tint_wgsl_fuzzer", "tint_tests", "seconds_3600", "iter_1"), tasks[0].TaskDir)

	lastIdx := len(tasks) - 1
	require.Equal(t, ExperimentLimitTypeRuns, tasks[lastIdx].LimitType)
	require.Equal(t, 100000, tasks[lastIdx].LimitValue)
	require.Equal(t, 2, tasks[lastIdx].Iteration)
	require.Equal(t, filepath.Join("/root/results/default", "tint_wgsl_fuzzer", "tint_tests", "runs_100000", "iter_2"), tasks[lastIdx].TaskDir)
	}

	func TestLoadExperimentSettings(t *testing.T) {
	tests := []struct {
	name string
	setupFS func(fs oswrapper.FSTestOSWrapper)
	wantErr bool
	errContains string
	validate func(t *testing.T, settings ExperimentSettings)
	}{
	{
	name: "Valid experiment config",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10},
	{"runs": 1000}
	]
	}`), 0644)
	},
	wantErr: false,
	validate: func(t *testing.T, settings ExperimentSettings) {
	require.Nil(t, settings.BenchmarkDuration)
	},
	},
	{
	name: "Valid experiment config with benchmark duration",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10},
	{"runs": 1000}
	],
	"benchmark_duration": 45
	}`), 0644)
	},
	wantErr: false,
	validate: func(t *testing.T, settings ExperimentSettings) {
	require.NotNil(t, settings.BenchmarkDuration)
	require.Equal(t, 45, *settings.BenchmarkDuration)
	},
	},
	{
	name: "Valid experiment config with burn-in duration and enabled",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	],
	"burnin_duration": 120,
	"burnin_enabled": false
	}`), 0644)
	},
	wantErr: false,
	validate: func(t *testing.T, config ExperimentSettings) {
	require.NotNil(t, config.BurnInDuration)
	require.Equal(t, 120, *config.BurnInDuration)
	require.NotNil(t, config.BurnInEnabled)
	require.False(t, *config.BurnInEnabled)
	},
	},
	{
	name: "Invalid experiment config (both limit types set)",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10, "runs": 1000}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "has both 'seconds' and 'runs' defined",
	},
	{
	name: "Invalid experiment config (neither limit type set)",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.MkdirAll("/root/corpora/test_corp", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"iterations": 5}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "must define either 'seconds' or 'runs'",
	},
	{
	name: "Missing config file",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	},
	wantErr: true,
	errContains: "experiment configuration file '/root/experiment.json' not found",
	},
	{
	name: "No fuzzers specified",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": [],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "no fuzzers specified in 'fuzzers' list",
	},
	{
	name: "Unsupported fuzzer",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["invalid_fuzzer_name"],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "unsupported fuzzer 'invalid_fuzzer_name'",
	},
	{
	name: "Missing WGSL benchmark corpus",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "wgsl_benchmark_corpus is required in experiment.json because WGSL fuzzers are specified",
	},
	{
	name: "Missing WGSL corpora",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "at least one wgsl_corpora definition is required in experiment.json because WGSL fuzzers are specified",
	},
	{
	name: "WGSL benchmark corpus directory missing",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "wgsl benchmark corpus directory 'bench' not found under corpora root",
	},
	{
	name: "WGSL corpus directory missing",
	setupFS: func(fs oswrapper.FSTestOSWrapper) {
	_ = fs.MkdirAll("/root/corpora/bench", 0755)
	_ = fs.WriteFile("/root/experiment.json", []byte(`{
	"name": "test_exp",
	"hash": "abcdef",
	"fuzzers": ["tint_wgsl_fuzzer"],
	"wgsl_benchmark_corpus": "bench",
	"wgsl_corpora": [
	{"name": "corp1", "path": "test_corp"}
	],
	"default_iterations": 2,
	"durations": [
	{"seconds": 10}
	]
	}`), 0644)
	},
	wantErr: true,
	errContains: "wgsl corpus directory 'test_corp' not found under corpora root",
	},
	}

	for _, tc := range tests {
	t.Run(tc.name, func(t *testing.T) {
	fs := oswrapper.CreateFSTestOSWrapper()
	tc.setupFS(fs)

	cfg := &taskConfig{
	mainConfig: mainConfig{
	osWrapper: fs,
	},
	}

	settings, err := loadExperimentSettings(cfg, "/root")
	if tc.wantErr {
	require.Error(t, err)
	require.Contains(t, err.Error(), tc.errContains)
	} else {
	require.NoError(t, err)
	require.Equal(t, "test_exp", settings.Name)
	if tc.validate != nil {
	tc.validate(t, settings)
	}
	}
	})
	}
	}