Fix bug in CombinedConfig: need to allow for config values not defined in the possible CLI args.

Nim's `terminal` library provides ANSI terminal escape support, but
only when writing directly to a File handle. This commit adds the
`term{FG,BG}` procedures and `termReset` constant to help with embedding
ANSI escape codes in string data.

cliutils.nim

@@ -1,4 +1,4 @@
-import docopt, json, osproc, posix, nre, streams, strtabs, unicode
+import docopt, json, osproc, posix, nre, streams, strtabs, tables, terminal, unicode
 import os except sleep
 import strutils except toUpper, toLower
 
@@ -8,12 +8,14 @@ type
     docopt*: Table[string, Value]
     json*: JsonNode
 
-proc getVal*(cfg: CombinedConfig, key, default: string): string =
+  TermColor = ForegroundColor or BackgroundColor
+
+proc getVal*(cfg: CombinedConfig, key: string): string =
   let argKey = "--" & key
   let envKey = key.replace('-', '_').toUpper
   let jsonKey = key.replace(re"(-\w)", proc (m: RegexMatch): string = ($m)[1..1].toUpper)
 
-  if cfg.docopt[argKey]: return $cfg.docopt[argKey]
+  if cfg.docopt.contains(argKey) and cfg.docopt[argKey]: return $cfg.docopt[argKey]
   elif existsEnv(envKey): return getEnv(envKey)
   elif cfg.json.hasKey(jsonKey):
     let node = cfg.json[jsonKey]
@@ -25,8 +27,11 @@ proc getVal*(cfg: CombinedConfig, key, default: string): string =
     of JNull: return ""
     of JObject: return $node
     of JArray: return $node
-  else: return default
+  else: raise newException(ValueError, "cannot find a configuration value for \"" & key & "\"")
 
+proc getVal*(cfg: CombinedConfig, key, default: string): string =
+  try: return getVal(cfg, key)
+  except: return default
 
 proc loadEnv*(): StringTableRef =
   result = newStringTable()
@@ -39,20 +44,20 @@ type HandleProcMsgCB* = proc (outMsg: TaintedString,
                               errMsg: TaintedString, cmd: string): void
 
 proc sendMsg*(h: HandleProcMsgCB, outMsg: TaintedString,
-              errMsg: TaintedString = nil, cmd: string = ""): void =
+              errMsg: TaintedString = "", cmd: string = ""): void =
   if h != nil: h(outMsg, errMsg, cmd)
 
 proc makeProcMsgHandler*(outSink, errSink: File, prefixCmd: bool = true): HandleProcMsgCB =
   result = proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
-    let prefix = if cmd == nil or not prefixCmd: "" else: cmd & ": "
+    let prefix = if cmd.len == 0 or not prefixCmd: "" else: cmd & ": "
-    if outMsg != nil: outSink.writeLine(prefix & outMsg)
+    if outMsg.len > 0: outSink.writeLine(prefix & outMsg)
-    if errMsg != nil: errSink.writeLine(prefix & errMsg)
+    if errMsg.len > 0: errSink.writeLine(prefix & errMsg)
 
 proc makeProcMsgHandler*(outSink, errSink: Stream, prefixCmd: bool = true): HandleProcMsgCB =
   result = proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
-    let prefix = if cmd == nil or not prefixCmd: "" else: cmd & ": "
+    let prefix = if cmd.len == 0 or not prefixCmd: "" else: cmd & ": "
-    if outMsg != nil: outSink.writeLine(prefix & outMsg)
+    if outMsg.len > 0: outSink.writeLine(prefix & outMsg)
-    if errMsg != nil: errSink.writeLine(prefix & errMsg)
+    if errMsg.len > 0: errSink.writeLine(prefix & errMsg)
 
 proc combineProcMsgHandlers*(a, b: HandleProcMsgCB): HandleProcMsgCB =
   if a == nil: result = b
@@ -70,9 +75,9 @@ proc waitFor*(p: Process, msgCB: HandleProcMsgCB, procCmd: string = ""): int =
   var line = newStringOfCap(120).TaintedString
   while true:
     if pout.readLine(line):
-      msgCB.sendMsg(line, nil, procCmd)
+      msgCB.sendMsg(line, "", procCmd)
     elif perr.readLine(line):
-      msgCB.sendMsg(nil, line, procCmd)
+      msgCB.sendMsg("", line, procCmd)
     else:
       result = peekExitCode(p)
       if result != -1: break
@@ -91,15 +96,15 @@ proc execWithOutput*(command: string, workingDir:string = "",
            args: openArray[string] = [], env: StringTableRef = nil,
            options: set[ProcessOption] = {poUsePath},
            msgCB: HandleProcMsgCB = nil):
-    tuple[output: TaintedString, error: TaintedString, exitCode: int] =
+    tuple[output, error: TaintedString, exitCode: int] =
 
   result = (TaintedString"", TaintedString"", -1)
   var outSeq, errSeq: seq[TaintedString]
   outSeq = @[]; errSeq = @[]
   var outputCollector = combineProcMsgHandlers(msgCB,
     proc(outMsg, errMsg: TaintedString, cmd: string): void {.closure.} =
-      if outMsg != nil: outSeq.add(outMsg)
+      if outMsg.len > 0: outSeq.add(outMsg)
-      if errMsg != nil: errSeq.add(errMsg))
+      if errMsg.len > 0: errSeq.add(errMsg))
 
   result[2] = exec(command, workingDir, args, env, options, outputCollector)
   result[0] = outSeq.join("\n")
@@ -145,15 +150,15 @@ proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): Pid =
     flushFile(stdout)
     flushFile(stderr)
 
-    if not si.isNil and si != "":
+    if si.len > 0:
       fi = open(si, fmRead)
       discard dup2(getFileHandle(fi), getFileHandle(stdin))
 
-    if not so.isNil and so != "":
+    if so.len > 0:
       fo = open(so, fmAppend)
       discard dup2(getFileHandle(fo), getFileHandle(stdout))
 
-    if not se.isNil and so != "":
+    if se.len > 0:
       fe = open(se, fmAppend)
       discard dup2(getFileHandle(fe), getFileHandle(stderr))
 
@@ -171,3 +176,39 @@ proc daemonize*(pidfile, si, so, se: string, daemonMain: proc(): void): Pid =
     daemonMain()
 
   return pid1
+
+const termReset* = "\e[0;m"
+
+proc termColor*(color: TermColor, bright, bold = false): string =
+  var colorVal = ord(color)
+  if bright: inc(colorVal, 60)
+  return "\e[" & $colorVal & (if bold: ";1" else: "") & "m"
+
+proc withColor*(str: string, color: TermColor, bright, bold = false): string =
+  return termColor(color, bright, bold) & str
+
+let STRIP_ANSI_REGEX = re"\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]"
+
+proc stripAnsi*(str: string): string = return str.replace(STRIP_ANSI_REGEX, "")
+
+proc queryParamsToCliArgs*(queryParams: Table[string, string]): seq[string] =
+  result = @[]
+
+  for k,v in queryParams:
+    # support ?arg1=val1&arg2=val2 -> cmd val1 val2
+    if k.startsWith("arg"): result.add(v)
+
+    else :
+      result[1].add("--" & k)
+      if v != "true": result[1].add(v) # support things like ?verbose=true -> cmd --verbose
+
+proc queryParamsToCliArgs*(queryParams: StringTableRef): seq[string] =
+  result = @[]
+
+  for k,v in queryParams:
+    # support ?arg1=val1&arg2=val2 -> cmd val1 val2
+    if k.startsWith("arg"): result.add(v)
+
+    else :
+      result.add("--" & k)
+      if v != "true": result.add(v) # support things like ?verbose=true -> cmd --verbose

cliutils.nimble

@@ -1,11 +1,11 @@
 # Package
 
-version       = "0.3.5"
+version       = "0.6.3"
 author        = "Jonathan Bernard"
 description   = "Helper functions for writing command line interfaces."
 license       = "MIT"
 
 # Dependencies
 
-requires @["nim >= 0.18.0", "docopt"]
+requires @["nim >= 0.19.0", "docopt >= 0.6.8"]