Fix issue #17: 0 columns does weird wrapping

Author: xenomachina

src/main/kotlin/com/xenomachina/argparser/DefaultHelpFormatter.kt

@@ -70,14 +70,19 @@ class DefaultHelpFormatter(
             columns: Int,
             values: List<HelpFormatter.Value>
     ): String {
+        val effectiveColumns = when {
+            columns < 0 -> throw IllegalArgumentException("columns must be non-negative")
+            columns == 0 -> Int.MAX_VALUE
+            else -> columns
+        }
         val sb = StringBuilder()
-        appendUsage(sb, columns, progName, values)
+        appendUsage(sb, effectiveColumns, progName, values)
         sb.append("\n")
 
         if (!prologue.isNullOrEmpty()) {
             sb.append("\n")
             // we just checked that prologue is non-null
-            sb.append(prologue!!.wrapText(columns))
+            sb.append(prologue!!.wrapText(effectiveColumns))
             sb.append("\n")
         }
 
@@ -92,19 +97,23 @@ class DefaultHelpFormatter(
                 else -> optional
             }.add(value)
         }
-        // Make left column as narrow as possible without wrapping any of the individual usages, though no wider than
-        // half the screen.
-        val usageColumns = (2 * indentWidth - 1 + (
-                values.map { usageText(it).split(" ").map { it.length }.max() ?: 0 }.max() ?: 0)
-                ).coerceAtMost(columns / 2)
-        appendSection(sb, usageColumns, columns, "required", required)
-        appendSection(sb, usageColumns, columns, "optional", optional)
-        appendSection(sb, usageColumns, columns, "positional", positional)
+        val usageColumns = 2 * indentWidth - 1 + if (columns == 0) {
+            values.map { usageText(it).length }.max() ?: 0
+        } else {
+            // Make left column as narrow as possible without wrapping any of the individual usages, though no wider than
+            // half the screen.
+                    values.map { usageText(it).split(" ").map { it.length }.max() ?: 0 }.max() ?: 0
+                    .coerceAtMost(effectiveColumns / 2)
+        }
+
+        appendSection(sb, usageColumns, effectiveColumns, "required", required)
+        appendSection(sb, usageColumns, effectiveColumns, "optional", optional)
+        appendSection(sb, usageColumns, effectiveColumns, "positional", positional)
 
         if (!epilogue?.trim().isNullOrEmpty()) {
             sb.append("\n")
             // we just checked that epilogue is non-null
-            sb.append(epilogue!!.trim().wrapText(columns))
+            sb.append(epilogue!!.trim().wrapText(effectiveColumns))
             sb.append("\n")
         }
 

src/main/kotlin/com/xenomachina/argparser/HelpFormatter.kt

@@ -27,7 +27,8 @@ interface HelpFormatter {
      *
      * @param progName name of the program as it should appear in usage information, or null if
      * program name is unknown.
-     * @param columns width of display help should be formatted for, measured in character cells.
+     * @param columns width of display help should be formatted for, measured in character cells, or 0 for infinite
+     * width.
      * @param values [Value] objects describing the arguments types available.
      */
     fun format(progName: String?, columns: Int, values: List<Value>): String

src/test/kotlin/com/xenomachina/argparser/ArgParserTest.kt

@@ -1047,6 +1047,38 @@ consectetur adipiscing elit. Donec vel tortor nunc. Sed eu
 massa sed turpis auctor faucibus. Donec vel pellentesque
 tortor. Ut ultrices tempus lectus fermentum vestibulum.
 Phasellus.
+""".trimStart()
+
+        // Regression test for issue #17
+        val help_wide = StringWriter().apply { printUserMessage(this, "program_name", 0) }.toString()
+        help_wide shouldBe """
+usage: program_name [-h] [-n] [-I INCLUDE]... -o OUTPUT [-v]... SOURCE... DEST
+
+
+This is the prologue. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aliquam malesuada maximus eros. Fusce luctus risus eget quam consectetur, eu auctor est ullamcorper. Maecenas eget suscipit dui, sed sodales erat. Phasellus.
+
+
+required arguments:
+  -o OUTPUT, --output OUTPUT      directory in which all output should be generated
+
+
+optional arguments:
+  -h, --help                      show this help message and exit
+
+  -n, --dry-run                   don't do anything
+
+  -I INCLUDE, --include INCLUDE   search in this directory for header files
+
+  -v, --verbose                   increase verbosity
+
+
+positional arguments:
+  SOURCE                          source file
+
+  DEST                            destination file
+
+
+This is the epilogue. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec vel tortor nunc. Sed eu massa sed turpis auctor faucibus. Donec vel pellentesque tortor. Ut ultrices tempus lectus fermentum vestibulum. Phasellus.
 """.trimStart()
     }
 })
@@ -1435,4 +1467,4 @@ optional arguments:
 
   --baz QUUX                   test help message""".trim()
     }
-})
+})