Merge pull request #313 from AndrejMitrovic/SpellCheck

Add spellchecker to dub for --config mismatches.

source/dub/commandline.d

@@ -19,7 +19,7 @@ import dub.packagemanager;
 import dub.packagesupplier;
 import dub.platform : determineCompiler;
 import dub.project;
-import dub.internal.utils : getDUBVersion;
+import dub.internal.utils : getDUBVersion, getClosestMatch;
 
 import std.algorithm;
 import std.array;
@@ -372,7 +372,14 @@ abstract class PackageBuildCommand : Command {
 		m_defaultConfig = null;
 		enforce (loadSpecificPackage(dub, package_name), "Failed to load package.");
 
-		enforce(m_buildConfig.length == 0 || dub.configurations.canFind(m_buildConfig), "Unknown build configuration: "~m_buildConfig);
+		if (m_buildConfig.length != 0 && !dub.configurations.canFind(m_buildConfig))
+		{
+			string msg = "Unknown build configuration: "~m_buildConfig;
+			enum distance = 3;
+			if (auto match = dub.configurations.getClosestMatch(m_buildConfig, distance))
+				msg ~= ". Did you mean '" ~ match ~ "'?";
+			enforce(0, msg);
+		}
 
 		if (m_buildType.length == 0) {
 			if (environment.get("DFLAGS")) m_buildType = "$DFLAGS";

source/dub/internal/utils.d

@@ -1,6 +1,6 @@
 /**
 	...
-	
+
 	Copyright: © 2012 Matthias Dondorff
 	License: Subject to the terms of the MIT license, as written in the included LICENSE.txt file.
 	Authors: Matthias Dondorff
@@ -208,4 +208,20 @@ private bool isHexNumber(string str) {
 			default: return false;
 		}
 	return true;
-}
+}
+
+/**
+    Get the closest match of $(D input) in the $(D array), where $(D distance)
+    is the maximum levenshtein distance allowed between the compared strings.
+    Returns $(D null) if no closest match is found.
+*/
+string getClosestMatch(string[] array, string input, size_t distance)
+{
+	import std.algorithm : countUntil, map, levenshteinDistance;
+	import std.uni : toUpper;
+
+	auto distMap = array.map!(elem =>
+		levenshteinDistance!((a, b) => toUpper(a) == toUpper(b))(elem, input));
+	auto idx = distMap.countUntil!(a => a <= distance);
+	return (idx == -1) ? null : array[idx];
+}