[#13] Add MediaType ^MT command (#26)

* [#13] Add MediaType `^MT` command

- Adds `MediaType` with extension function `mediaType`

* Suppress unused `ZplMediaType`

* Fix `MediaTypeTest` nesting

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

@@ -0,0 +1,30 @@
+package com.sainsburys.k2zpl.command
+
+import com.sainsburys.k2zpl.builder.ZplBuilder
+import com.sainsburys.k2zpl.command.options.ZplMediaType
+
+internal data class MediaType(
+    val type: ZplMediaType,
+) : ZplCommand {
+    override val command = "^MT"
+    override val parameters: ZplParameters = zplParameters(
+        "t" to type
+    )
+}
+
+/**
+ * Sets the media type for the label.
+ * Allows to set thermal vs. ribbon.
+ *
+ * The ^MT command selects the type of media being used in the printer.
+ *
+ * @param type The media type of the printer.
+ *
+ * [ZplMediaType.THERMAL_TRANSFER] – this media uses a high-carbon black or colored ribbon. The ink on the ribbon is bonded to the media.
+ *
+ * [ZplMediaType.DIRECT_TRANSFER] – this media is heat sensitive and requires no ribbon.
+ *
+ */
+fun ZplBuilder.mediaType(type: ZplMediaType) {
+    command(MediaType(type))
+}

src/main/kotlin/com/sainsburys/k2zpl/command/options/ZplMediaType.kt

@@ -0,0 +1,12 @@
+@file:Suppress("UNUSED")
+
+package com.sainsburys.k2zpl.command.options
+
+enum class ZplMediaType(val value: String) {
+    THERMAL_TRANSFER("T"),
+    DIRECT_TRANSFER("D");
+
+    override fun toString(): String {
+        return value
+    }
+}

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

@@ -0,0 +1,44 @@
+package com.sainsburys.k2zpl.command
+
+import com.sainsburys.k2zpl.command.options.ZplMediaType
+import com.sainsburys.k2zpl.k2zpl
+import com.sainsburys.k2zpl.testBuildString
+import io.kotest.core.spec.IsolationMode
+import io.kotest.core.spec.style.DescribeSpec
+import io.kotest.data.forAll
+import io.kotest.data.headers
+import io.kotest.data.row
+import io.kotest.data.table
+import io.kotest.matchers.shouldBe
+
+class MediaTypeTest : DescribeSpec({
+
+    isolationMode = IsolationMode.InstancePerLeaf
+
+    describe("MediaType") {
+
+        val subject = MediaType(type = ZplMediaType.DIRECT_TRANSFER)
+
+        it("outputs correct command") {
+            table(
+                headers("media type"),
+                ZplMediaType.entries.map { row(it) }
+            ).forAll { type ->
+                subject.copy(type = type).testBuildString() shouldBe "^MT${type}"
+            }
+        }
+    }
+    describe("mediaType extension function") {
+        it("outputs correct command") {
+            table(
+                headers("media type"),
+                ZplMediaType.entries.map { row(it) }
+            ).forAll { type ->
+                val result = k2zpl {
+                    mediaType(type)
+                }
+                result shouldBe "^MT${type}\n"
+            }
+        }
+    }
+})