diff --git a/unittest/force-styles/test_angle_style.cpp b/unittest/force-styles/test_angle_style.cpp
index ff391127bd..05646a93a9 100644
--- a/unittest/force-styles/test_angle_style.cpp
+++ b/unittest/force-styles/test_angle_style.cpp
@@ -38,7 +38,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -235,48 +234,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
 
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // skip tests
-    block.clear();
-    for (auto &skip_tests : config.skip_tests) {
-        if (block.empty()) block = skip_tests;
-        else block += " " + skip_tests;
-    }
-    writer.emit("skip_tests", block);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // angle_style
     writer.emit("angle_style", config.angle_style);
diff --git a/unittest/force-styles/test_bond_style.cpp b/unittest/force-styles/test_bond_style.cpp
index 94d2344c03..f3aab53b12 100644
--- a/unittest/force-styles/test_bond_style.cpp
+++ b/unittest/force-styles/test_bond_style.cpp
@@ -38,7 +38,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -235,48 +234,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
 
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // skip tests
-    block.clear();
-    for (auto &skip_tests : config.skip_tests) {
-        if (block.empty()) block = skip_tests;
-        else block += " " + skip_tests;
-    }
-    writer.emit("skip_tests", block);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // bond_style
     writer.emit("bond_style", config.bond_style);
diff --git a/unittest/force-styles/test_dihedral_style.cpp b/unittest/force-styles/test_dihedral_style.cpp
index f8ad0a60eb..95f64d7896 100644
--- a/unittest/force-styles/test_dihedral_style.cpp
+++ b/unittest/force-styles/test_dihedral_style.cpp
@@ -38,7 +38,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -244,40 +243,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
 
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // dihedral_style
     writer.emit("dihedral_style", config.dihedral_style);
diff --git a/unittest/force-styles/test_fix_timestep.cpp b/unittest/force-styles/test_fix_timestep.cpp
index 3fa2e78813..6ba3f7f6d7 100644
--- a/unittest/force-styles/test_fix_timestep.cpp
+++ b/unittest/force-styles/test_fix_timestep.cpp
@@ -42,7 +42,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -193,48 +192,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
     std::string block("");
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // skip tests
-    block.clear();
-    for (auto &skip_tests : config.skip_tests) {
-        if (block.empty()) block = skip_tests;
-        else block += " " + skip_tests;
-    }
-    writer.emit("skip_tests", block);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // natoms
     writer.emit("natoms", natoms);
diff --git a/unittest/force-styles/test_improper_style.cpp b/unittest/force-styles/test_improper_style.cpp
index 9e38c03cd1..2e61a1e0cb 100644
--- a/unittest/force-styles/test_improper_style.cpp
+++ b/unittest/force-styles/test_improper_style.cpp
@@ -38,7 +38,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -235,48 +234,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
 
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // skip tests
-    block.clear();
-    for (auto &skip_tests : config.skip_tests) {
-        if (block.empty()) block = skip_tests;
-        else block += " " + skip_tests;
-    }
-    writer.emit("skip_tests", block);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // improper_style
     writer.emit("improper_style", config.improper_style);
diff --git a/unittest/force-styles/test_main.cpp b/unittest/force-styles/test_main.cpp
index 69a2b96822..e26eb6a8fb 100644
--- a/unittest/force-styles/test_main.cpp
+++ b/unittest/force-styles/test_main.cpp
@@ -16,16 +16,19 @@
 #include "test_config.h"
 #include "test_config_reader.h"
 #include "utils.h"
+#include "yaml_writer.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
 #include <cstdlib>
 #include <cstring>
+#include <ctime>
 #include <iostream>
 #include <mpi.h>
 #include <vector>
 
 using LAMMPS_NS::utils::split_words;
+using LAMMPS_NS::utils::trim;
 
 // common read_yaml_file function
 bool read_yaml_file(const char *infile, TestConfig &config)
@@ -37,6 +40,55 @@ bool read_yaml_file(const char *infile, TestConfig &config)
     return true;
 }
 
+// write out common header items for yaml files
+void write_yaml_header(YamlWriter *writer,
+                       TestConfig *cfg,
+                       const char *version)
+{
+    // lammps_version
+    writer->emit("lammps_version", version);
+
+    // date_generated
+    std::time_t now = time(NULL);
+    std::string block = trim(ctime(&now));
+    writer->emit("date_generated", block);
+
+    // epsilon
+    writer->emit("epsilon", cfg->epsilon);
+
+    // skip tests
+    block.clear();
+    for (auto &skip : cfg->skip_tests) {
+        if (block.empty()) block = skip;
+        else block += " " + skip;
+    }
+    writer->emit("skip_tests", block);
+
+    // prerequisites
+    block.clear();
+    for (auto &prerequisite : cfg->prerequisites) {
+        block += prerequisite.first + " " + prerequisite.second + "\n";
+    }
+    writer->emit_block("prerequisites", block);
+
+    // pre_commands
+    block.clear();
+    for (auto &command : cfg->pre_commands) {
+        block += command + "\n";
+    }
+    writer->emit_block("pre_commands", block);
+
+    // post_commands
+    block.clear();
+    for (auto &command : cfg->post_commands) {
+        block += command + "\n";
+    }
+    writer->emit_block("post_commands", block);
+
+    // input_file
+    writer->emit("input_file", cfg->input_file);
+}
+
 // need to be defined in unit test body
 extern void generate_yaml_file(const char *, const TestConfig &);
 
diff --git a/unittest/force-styles/test_main.h b/unittest/force-styles/test_main.h
index ee0be2a637..0f30467f6b 100644
--- a/unittest/force-styles/test_main.h
+++ b/unittest/force-styles/test_main.h
@@ -22,6 +22,10 @@ extern bool print_stats;
 extern bool verbose;
 extern std::string INPUT_FOLDER;
 
+// convenience method to write out common entries
+void write_yaml_header(class YamlWriter *writer, TestConfig *cfg,
+                       const char *version);
+
 #define EXPECT_FP_LE_WITH_EPS(val1, val2, eps)                \
     do {                                                      \
         const double diff = fabs(val1 - val2);                \
@@ -31,10 +35,11 @@ extern std::string INPUT_FOLDER;
         EXPECT_PRED_FORMAT2(::testing::DoubleLE, err, eps);   \
     } while (0);
 
-#endif
-
 #if defined _WIN32
 static const char PATH_SEP = '\\';
 #else
 static const char PATH_SEP = '/';
 #endif
+
+#endif
+
diff --git a/unittest/force-styles/test_pair_style.cpp b/unittest/force-styles/test_pair_style.cpp
index 0e61bacfbd..6a99fb72cd 100644
--- a/unittest/force-styles/test_pair_style.cpp
+++ b/unittest/force-styles/test_pair_style.cpp
@@ -40,7 +40,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <ctime>
 #include <mpi.h>
 
 #include <map>
@@ -244,48 +243,8 @@ void generate_yaml_file(const char *outfile, const TestConfig &config)
 
     YamlWriter writer(outfile);
 
-    // lammps_version
-    writer.emit("lammps_version", lmp->version);
-
-    // date_generated
-    std::time_t now = time(NULL);
-    block           = utils::trim(ctime(&now));
-    writer.emit("date_generated", block);
-
-    // epsilon
-    writer.emit("epsilon", config.epsilon);
-
-    // skip tests
-    block.clear();
-    for (auto &skip_tests : config.skip_tests) {
-        if (block.empty()) block = skip_tests;
-        else block += " " + skip_tests;
-    }
-    writer.emit("skip_tests", block);
-
-    // prerequisites
-    block.clear();
-    for (auto &prerequisite : config.prerequisites) {
-        block += prerequisite.first + " " + prerequisite.second + "\n";
-    }
-    writer.emit_block("prerequisites", block);
-
-    // pre_commands
-    block.clear();
-    for (auto &command : config.pre_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("pre_commands", block);
-
-    // post_commands
-    block.clear();
-    for (auto &command : config.post_commands) {
-        block += command + "\n";
-    }
-    writer.emit_block("post_commands", block);
-
-    // input_file
-    writer.emit("input_file", config.input_file);
+    // write yaml header
+    write_yaml_header(&writer, &test_config, lmp->version);
 
     // pair_style
     writer.emit("pair_style", config.pair_style);