diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4f2ac1baa..650a5ea52 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,11 +1,17 @@
 # Changelog
 
+## Unreleased
+
+**Fixes**:
+
+- Check file-writer construction when writing envelope to path. ([#1036](https://github.com/getsentry/sentry-native/pull/1036))
+ 
 ## 0.7.8
 
 **Features**:
 
 - Let the envelope serialization stream directly to the file. ([#1021](https://github.com/getsentry/sentry-native/pull/1021))
-- Support 16kb page sizes on Android 15 ([#1028](https://github.com/getsentry/sentry-native/pull/1028))
+- Support 16kb page sizes on Android 15. ([#1028](https://github.com/getsentry/sentry-native/pull/1028))
 
 ## 0.7.7
 
diff --git a/include/sentry.h b/include/sentry.h
index 29df6ae5d..5753c2cef 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -1366,6 +1366,9 @@ SENTRY_API sentry_uuid_t sentry_capture_event(sentry_value_t event);
  * Captures an exception to be handled by the backend.
  *
  * This is safe to be called from a crashing thread and may not return.
+ *
+ * Note: The `crashpad` client currently supports this only on Windows. `inproc`
+ *       and `breakpad` support it on all platforms.
  */
 SENTRY_EXPERIMENTAL_API void sentry_handle_exception(
     const sentry_ucontext_t *uctx);
diff --git a/scripts/run_tests.ps1 b/scripts/run_tests.ps1
new file mode 100644
index 000000000..0f5345d76
--- /dev/null
+++ b/scripts/run_tests.ps1
@@ -0,0 +1,40 @@
+param (
+    [switch]$Unit = $false,
+    [switch]$Clean = $false,
+    [string]$Keyword = "",
+    [int]$Parallelism = 1,
+    [switch]$WithoutCrashpadWer = $false
+)
+
+$update_test_discovery = Join-Path -Path $PSScriptRoot -ChildPath "update_test_discovery.ps1"
+& $update_test_discovery
+
+if ($Clean -or -not (Test-Path .\.venv))
+{
+    Remove-Item -Recurse -Force .\.venv\ -ErrorAction SilentlyContinue
+    python3.exe -m venv .venv
+    .\.venv\Scripts\pip.exe install --upgrade --requirement .\tests\requirements.txt
+}
+
+$pytestCommand = ".\.venv\Scripts\pytest.exe .\tests\ --verbose"
+
+if ($Parallelism -gt 1)
+{
+    $pytestCommand += " -n $Parallelism"
+}
+
+if (-not $WithoutCrashpadWer -and -not $Unit)
+{
+    $pytestCommand += " --with_crashpad_wer"
+}
+
+if ($Keyword)
+{
+    $pytestCommand += " -k `"$Keyword`""
+}
+elseif ($Unit)
+{
+    $pytestCommand += " -k `"unit`""
+}
+
+Invoke-Expression $pytestCommand
\ No newline at end of file
diff --git a/scripts/update_test_discovery.ps1 b/scripts/update_test_discovery.ps1
new file mode 100644
index 000000000..0a58f8e49
--- /dev/null
+++ b/scripts/update_test_discovery.ps1
@@ -0,0 +1,7 @@
+Get-ChildItem -Path 'tests/unit/*.c' | ForEach-Object {
+    Get-Content $_.FullName | ForEach-Object {
+        if ($_ -match 'SENTRY_TEST\(([^)]+)\)') {
+            $_ -replace 'SENTRY_TEST\(([^)]+)\)', 'XX($1)'
+        }
+    }
+} | Sort-Object | Where-Object { $_ -notmatch 'define' } | Get-Unique | Set-Content 'tests/unit/tests.inc'
diff --git a/src/path/sentry_path_windows.c b/src/path/sentry_path_windows.c
index bd989121f..b55ebbdf3 100644
--- a/src/path/sentry_path_windows.c
+++ b/src/path/sentry_path_windows.c
@@ -273,6 +273,9 @@ bool
 sentry__path_filename_matches(const sentry_path_t *path, const char *filename)
 {
     sentry_path_t *fn = sentry__path_from_str(filename);
+    if (!fn) {
+        return false;
+    }
     bool matches = _wcsicmp(sentry__path_filename(path), fn->path) == 0;
     sentry__path_free(fn);
     return matches;
@@ -282,6 +285,9 @@ bool
 sentry__path_ends_with(const sentry_path_t *path, const char *suffix)
 {
     sentry_path_t *s = sentry__path_from_str(suffix);
+    if (!s) {
+        return false;
+    }
     size_t pathlen = wcslen(path->path);
     size_t suffixlen = wcslen(s->path);
     if (suffixlen > pathlen) {
@@ -604,9 +610,9 @@ sentry__filewriter_write(
     }
     while (buf_len > 0) {
         size_t n = fwrite(buf, 1, buf_len, filewriter->f);
-        if (n < 0 && (errno == EAGAIN || errno == EINTR)) {
+        if (n == 0 && errno == EINVAL) {
             continue;
-        } else if (n <= 0) {
+        } else if (n < buf_len) {
             break;
         }
         filewriter->byte_count += n;
diff --git a/src/sentry_envelope.c b/src/sentry_envelope.c
index cffcb5e6e..e173e9494 100644
--- a/src/sentry_envelope.c
+++ b/src/sentry_envelope.c
@@ -477,6 +477,9 @@ sentry_envelope_write_to_path(
     const sentry_envelope_t *envelope, const sentry_path_t *path)
 {
     sentry_filewriter_t *fw = sentry__filewriter_new(path);
+    if (!fw) {
+        return 1;
+    }
 
     if (envelope->is_raw) {
         return envelope->contents.raw.payload_len
diff --git a/tests/unit/test_envelopes.c b/tests/unit/test_envelopes.c
index 803fb4730..8d0de1fc5 100644
--- a/tests/unit/test_envelopes.c
+++ b/tests/unit/test_envelopes.c
@@ -253,3 +253,19 @@ SENTRY_TEST(write_envelope_to_file_null)
 
     sentry_envelope_free(empty_envelope);
 }
+
+SENTRY_TEST(write_envelope_to_invalid_path)
+{
+    sentry_envelope_t *envelope = create_test_envelope();
+    const char *test_file_str
+        = "./directory_that_does_not_exist/sentry_test_envelope";
+    sentry_path_t *test_file_path = sentry__path_from_str(test_file_str);
+
+    int rv = sentry_envelope_write_to_file(envelope, test_file_str);
+    TEST_CHECK_INT_EQUAL(rv, 1);
+
+    sentry__path_remove(test_file_path);
+    sentry__path_free(test_file_path);
+    sentry_envelope_free(envelope);
+    sentry_close();
+}
diff --git a/tests/unit/tests.inc b/tests/unit/tests.inc
index 0f0db85db..cc7920bc1 100644
--- a/tests/unit/tests.inc
+++ b/tests/unit/tests.inc
@@ -137,3 +137,4 @@ XX(value_string_n)
 XX(value_unicode)
 XX(value_wrong_type)
 XX(write_envelope_to_file_null)
+XX(write_envelope_to_invalid_path)