fix(sdcard): IsNonResultLine no longer false-positives on filenames starting with 'error' (#190)

src/Daqifi.Core.Tests/Device/SdCard/SdCardOperationsTests.cs

@@ -68,6 +68,33 @@ public async Task GetSdCardFilesAsync_ParsesResponseCorrectly()
             Assert.Null(files[1].CreatedDate);
         }
 
+        [Fact]
+        public async Task GetSdCardFilesAsync_FilenamesStartingWithErrorAreNotMisclassified()
+        {
+            // Regression for #190: IsNonResultLine's prior bare "ERROR"
+            // prefix check false-positived on legit SD filenames whose
+            // basename starts with "error" (e.g. "error_log.csv"). The
+            // permissive classifier dropped them from the parsed file
+            // list. Tightened to require ERROR followed by `:`/` `/`!`/
+            // tab so ordinary filenames pass through.
+            var device = new TestableSdCardStreamingDevice("TestDevice");
+            device.CannedTextResponse = new List<string>
+            {
+                "Daqifi/error_log.csv",
+                "Daqifi/Errors_summary.bin",
+                "Daqifi/normal.bin",
+            };
+            device.Connect();
+
+            var files = await device.GetSdCardFilesAsync();
+
+            var names = files.Select(f => f.FileName).ToList();
+            Assert.Contains("error_log.csv", names);
+            Assert.Contains("Errors_summary.bin", names);
+            Assert.Contains("normal.bin", names);
+            Assert.Equal(3, files.Count);
+        }
+
         [Fact]
         public async Task GetSdCardFilesAsync_RestoresLanInterface()
         {

src/Daqifi.Core/Device/DaqifiStreamingDevice.cs

@@ -749,12 +749,29 @@ private static bool IsScpiErrorLine(string line)
         // Permissive: any line that looks like a device error or status message,
         // including firmware text such as "Error !! ...". Used to recognize that
         // the parser would yield no result, without polluting LastScpiError with
-        // non-SCPI text.
+        // non-SCPI text. Closes #190 — bare "ERROR" prefix false-positives on
+        // legit SD filenames that happen to start with "error" (e.g.
+        // "error_log.csv"), which would mask the file from GetSdCardFilesAsync's
+        // returned list. Tightened to require ERROR followed by ":", " " (firmware
+        // pattern "Error !!"), or "*" (the "**ERROR" SCPI marker, also matched by
+        // IsScpiErrorLine).
         private static bool IsNonResultLine(string line)
         {
             var trimmed = line.TrimStart();
-            return trimmed.StartsWith("**ERROR", StringComparison.OrdinalIgnoreCase)
-                || trimmed.StartsWith("ERROR", StringComparison.OrdinalIgnoreCase);
+            if (trimmed.StartsWith("**ERROR", StringComparison.OrdinalIgnoreCase))
+                return true;
+            // Must be followed by a non-letter so plain filenames like
+            // "error_log.csv" (which TrimStart leaves intact) don't match.
+            if (trimmed.Length >= 5
+                && trimmed.StartsWith("ERROR", StringComparison.OrdinalIgnoreCase))
+            {
+                if (trimmed.Length == 5)
+                    return true;
+                var next = trimmed[5];
+                if (next == ':' || next == ' ' || next == '!' || next == '\t')
+                    return true;
+            }
+            return false;
         }
 
         /// <summary>