exceptions-to-values.6 : Collect reasons for failure

Duncan McGregor · dmcg · commit 15cf851e2802 · 2021-07-28T21:55:01.000+01:00
diff --git a/src/main/java/travelator/marketing/HighValueCustomersMain.kt b/src/main/java/travelator/marketing/HighValueCustomersMain.kt
@@ -7,7 +7,7 @@ import kotlin.system.exitProcess
 fun main() {
     System.`in`.reader().use { reader ->
         System.out.writer().use { writer ->
-            val errorLines = mutableListOf<String>()
+            val errorLines = mutableListOf<ParseFailure>()
             val reportLines = reader
                 .asLineSequence()
                 .toHighValueCustomerReport {
@@ -16,7 +16,9 @@ fun main() {
             if (errorLines.isNotEmpty()) {
                 System.err.writer().use { error ->
                     error.appendLine("Lines with errors")
-                    errorLines.asSequence().writeTo(error)
+                    errorLines.asSequence().map { parseFailure ->
+                        "${parseFailure::class.simpleName} in ${parseFailure.line}"
+                    }.writeTo(error)
                 }
                 exitProcess(-1)
             } else {
diff --git a/src/main/java/travelator/marketing/HighValueCustomersReport.kt b/src/main/java/travelator/marketing/HighValueCustomersReport.kt
@@ -6,13 +6,13 @@ import com.natpryce.Success
 import com.natpryce.recover
 
 fun Sequence<String>.toHighValueCustomerReport(
-    onErrorLine: (String) -> Unit = {}
+    onErrorLine: (ParseFailure) -> Unit = {}
 ): Sequence<String> {
     val valuableCustomers = this
         .withoutHeader()
         .map { line ->
             line.toCustomerData().recover {
-                onErrorLine(line)
+                onErrorLine(it)
                 null
             }
         }
diff --git a/src/test/java/travelator/marketing/HighValueCustomersReportTests.kt b/src/test/java/travelator/marketing/HighValueCustomersReportTests.kt
@@ -54,14 +54,18 @@ class HighValueCustomersReportTests {
             "1\tFred\tFlintstone\t11\t1000.00",
         )
 
-        val errorCollector = mutableListOf<String>()
+        val errorCollector = mutableListOf<ParseFailure>()
         val result = lines
             .asSequence()
             .constrainOnce()
-            .toHighValueCustomerReport { badLine -> // <1>
+            .toHighValueCustomerReport { badLine ->
                 errorCollector += badLine
             }
             .toList()
+        assertEquals(
+            listOf(NotEnoughFieldsFailure("INVALID LINE")),
+            errorCollector
+        )
 
         assertEquals(
             listOf(
@@ -71,10 +75,6 @@ class HighValueCustomersReportTests {
             ),
             result
         )
-        assertEquals(
-            listOf("INVALID LINE"),
-            errorCollector
-        )
     }
 
 
