[CHORE] Add ZplParameters Wrapper (#21)

* [CHORE] Migrate use of `Map` and `LinkedHashMap` to wrapper `ZplParameters`

To enforce use of `LinkedHashMap` on `ZplCommand`, add a simple wrapper class that uses `LinkedHashMap` underneath.

* Add tests

* Make `ZplParameters` implement `Iterable` and adjust interface

* minor constructor adjustment

* PR Feedback - collapse iterator on `ZplCommand` to sequenced functions

* Add .idea/misc.xml to .gitignore

* PR feedback - simplify parameter stream

.gitignore

@@ -9,6 +9,7 @@ build/
 .idea/jarRepositories.xml
 .idea/compiler.xml
 .idea/libraries/
+.idea/misc.xml
 *.iws
 *.iml
 *.ipr

src/main/kotlin/com/sainsburys/k2zpl/command/BarCode.kt

@@ -20,7 +20,7 @@ internal data class BarCode(
     }
 
     override val command: CharSequence = "^B1"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "o" to orientation.code,
         "c" to checkDigit.toString(),
         "h" to height,

src/main/kotlin/com/sainsburys/k2zpl/command/FieldBlock.kt

@@ -18,7 +18,7 @@ internal data class FieldBlock(
     }
 
     override val command: CharSequence = "^FB"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "w" to width,
         "l" to maxLines,
         "s" to lineSpacing,

src/main/kotlin/com/sainsburys/k2zpl/command/FieldData.kt

@@ -4,7 +4,7 @@ import com.sainsburys.k2zpl.builder.ZplBuilder
 
 internal data class FieldData(val data: String) : ZplCommand {
     override val command: CharSequence = "^FD"
-    override val parameters: Map<CharSequence, Any?> = addParameters("d" to data)
+    override val parameters: ZplParameters = zplParameters("d" to data)
 
     override fun build(stringBuilder: StringBuilder): StringBuilder {
         return stringBuilder

src/main/kotlin/com/sainsburys/k2zpl/command/FieldOrigin.kt

@@ -14,7 +14,7 @@ internal data class FieldOrigin(
     }
 
     override val command: CharSequence = "^FO"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "x" to x,
         "y" to y,
         "j" to justification

src/main/kotlin/com/sainsburys/k2zpl/command/Font.kt

@@ -17,8 +17,8 @@ internal data class Font(
     }
 
     override val command: CharSequence = "^A${font}"
-    override val parameters: Map<CharSequence, Any?> =
-        addParameters("o" to orientation, "h" to height, "w" to width)
+    override val parameters: ZplParameters =
+        zplParameters("o" to orientation, "h" to height, "w" to width)
 }
 
 

src/main/kotlin/com/sainsburys/k2zpl/command/GraphicBox.kt

@@ -18,8 +18,8 @@ internal data class GraphicBox(
     }
 
     override val command: CharSequence = "^GB"
-    override val parameters: Map<CharSequence, Any?> =
-        addParameters(
+    override val parameters: ZplParameters =
+        zplParameters(
             "w" to width,
             "h" to height,
             "t" to thickness, "c" to color.code,

src/main/kotlin/com/sainsburys/k2zpl/command/GraphicField.kt

@@ -17,7 +17,7 @@ internal data class GraphicField(
     }
 
     override val command: CharSequence = "^GF"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "f" to format,
         "db" to dataBytes,
         "tb" to totalBytes,

src/main/kotlin/com/sainsburys/k2zpl/command/LabelHome.kt

@@ -4,7 +4,7 @@ import com.sainsburys.k2zpl.builder.ZplBuilder
 
 internal data class LabelHome(val x: Int, val y: Int) : ZplCommand {
     override val command: CharSequence = "^LH"
-    override val parameters: Map<CharSequence, Any?> = addParameters("x" to x, "y" to y)
+    override val parameters: ZplParameters = zplParameters("x" to x, "y" to y)
 }
 
 /**

src/main/kotlin/com/sainsburys/k2zpl/command/LabelLength.kt

@@ -8,7 +8,7 @@ internal data class LabelLength(val length: Int) : ZplCommand {
     }
 
     override val command: CharSequence = "^LL"
-    override val parameters: Map<CharSequence, Any?> = addParameters("l" to length)
+    override val parameters: ZplParameters = zplParameters("l" to length)
 }
 
 /**

src/main/kotlin/com/sainsburys/k2zpl/command/MediaMode.kt

@@ -10,8 +10,8 @@ internal data class MediaMode(
     val prePeelSelect: ZplYesNo
 ) : ZplCommand {
     override val command: CharSequence = "^MM"
-    override val parameters: Map<CharSequence, Any?> =
-        addParameters("m" to mediaMode, "p" to prePeelSelect)
+    override val parameters: ZplParameters =
+        zplParameters("m" to mediaMode, "p" to prePeelSelect)
 }
 
 /**

src/main/kotlin/com/sainsburys/k2zpl/command/PrintWidth.kt

@@ -8,7 +8,7 @@ internal data class PrintWidth(val width: Int) : ZplCommand {
     }
 
     override val command: CharSequence = "^PW"
-    override val parameters: Map<CharSequence, Any?> = addParameters("w" to width)
+    override val parameters: ZplParameters = zplParameters("w" to width)
 }
 
 

src/main/kotlin/com/sainsburys/k2zpl/command/ZplCommand.kt

@@ -2,31 +2,13 @@ package com.sainsburys.k2zpl.command
 
 interface ZplCommand {
     val command: CharSequence
-    val parameters: Map<CharSequence, Any?> get() = addParameters()
+    val parameters: ZplParameters get() = zplParameters()
     fun build(stringBuilder: StringBuilder) = stringBuilder.apply {
         append(command)
-        with(parameters.values.iterator()) {
-            if (hasNext()) {
-                nextNotNull { append(it.toString()) }
-            }
-            while (hasNext()) {
-                nextNotNull {
-                    if (length > command.length) {
-                        append(',')
-                    }
-                    append(it.toString())
-                }
-            }
-        }
+        parameters
+            .asSequence()
+            .mapNotNull { it.value?.toString() }
+            .filter(String::isNotBlank)
+            .joinTo(this, separator = ",")
     }
 }
-
-private fun <T> Iterator<T>.nextNotNull(block: (T) -> Unit) {
-    next()?.let { block(it) }
-}
-
-/**
- * A shortcut to adding parameters that helps to enforce use of [LinkedHashMap]
- * so that entry order is preserved.
- */
-internal fun <K, V> ZplCommand.addParameters(vararg pairs: Pair<K, V>) = linkedMapOf(*pairs)

src/main/kotlin/com/sainsburys/k2zpl/command/ZplParameters.kt

@@ -0,0 +1,12 @@
+package com.sainsburys.k2zpl.command
+
+class ZplParameters(map: Map<CharSequence, Any?>) : Iterable<Map.Entry<CharSequence, Any?>> {
+    constructor(vararg pairs: Pair<CharSequence, Any?>) : this(mapOf(*pairs))
+    private val _parameters: LinkedHashMap<CharSequence, Any?> = LinkedHashMap(map)
+    operator fun get(key: CharSequence) = _parameters[key]
+    override fun iterator(): Iterator<Map.Entry<CharSequence, Any?>> =
+        _parameters.iterator()
+}
+
+fun zplParameters(vararg pairs: Pair<CharSequence, Any?>) = ZplParameters(*pairs)
+fun zplParameters(builderBlock: MutableMap<CharSequence, Any?>.() -> Unit) = ZplParameters(buildMap(builderBlock))

src/test/kotlin/com/sainsburys/k2zpl/command/ZplCommandTest.kt

@@ -33,30 +33,30 @@ class ZplCommandWithoutParameters : ZplCommand {
 
 class ZplCommandWithOneParameter : ZplCommand {
     override val command = "^ZCP"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "param-one" to "value-one"
     )
 }
 
 class ZplCommandWithMultipleParameters : ZplCommand {
     override val command = "^ZCPS"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "param-one" to "value-one",
         "param-two" to "value-two"
     )
 }
 
 class ZplCommandWitNullFirstParameter : ZplCommand {
     override val command = "^ZCPN"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "param-one" to null,
         "param-two" to "value-two"
     )
 }
 
 class ZplCommandWitNullSecondParameter : ZplCommand {
     override val command = "^ZCPNS"
-    override val parameters: Map<CharSequence, Any?> = addParameters(
+    override val parameters: ZplParameters = zplParameters(
         "param-one" to "value-one",
         "param-two" to null
     )

src/test/kotlin/com/sainsburys/k2zpl/command/ZplParametersTest.kt

@@ -0,0 +1,73 @@
+package com.sainsburys.k2zpl.command
+
+import io.kotest.core.spec.IsolationMode
+import io.kotest.core.spec.style.DescribeSpec
+import io.kotest.matchers.shouldBe
+
+class ZplParametersTest : DescribeSpec({
+    isolationMode = IsolationMode.InstancePerLeaf
+
+    describe("ZplParameters pairs constructor") {
+        val result = ZplParameters("a" to "b", "c" to "d")
+        it("returns values passed to ZplParameters") {
+            result.forEachIndexed { index, param ->
+                when (index) {
+                    0 -> param.value shouldBe "b"
+                    1 -> param.value shouldBe "d"
+                }
+            }
+        }
+        it("makes values accessible by get operator") {
+            result["a"] shouldBe "b"
+            result["c"] shouldBe "d"
+        }
+    }
+    describe("ZplParameters map constructor") {
+        val result = ZplParameters(mapOf("a" to "b", "c" to "d"))
+        it("returns values passed to ZplParameters") {
+            result.forEachIndexed { index, param ->
+                when (index) {
+                    0 -> param.value shouldBe "b"
+                    1 -> param.value shouldBe "d"
+                }
+            }
+        }
+        it("makes values accessible by get operator") {
+            result["a"] shouldBe "b"
+            result["c"] shouldBe "d"
+        }
+    }
+    describe("zplParameters pairs function") {
+        val result = zplParameters("e" to "f", "g" to "h")
+        it("returns values passed to ZplParameters") {
+            result.forEachIndexed { index, param ->
+                when (index) {
+                    0 -> param.value shouldBe "f"
+                    1 -> param.value shouldBe "h"
+                }
+            }        }
+        it("makes values accessible by get operator") {
+            result["e"] shouldBe "f"
+            result["g"] shouldBe "h"
+        }
+    }
+
+    describe("ZplParameters builder function") {
+        val result = zplParameters {
+            put("a", "b")
+            put("c", "d")
+        }
+        it("returns values passed to ZplParameters") {
+            result.forEachIndexed { index, param ->
+                when (index) {
+                    0 -> param.value shouldBe "b"
+                    1 -> param.value shouldBe "d"
+                }
+            }
+        }
+        it("makes values accessible by get operator") {
+            result["a"] shouldBe "b"
+            result["c"] shouldBe "d"
+        }
+    }
+})