Explicitly require docopt v0.7.1 or above.

For example, if `false` happened to be the only value on a line, this
would be parsed as valid JSON (a boolean) but it is not a structured log
message that slfmt should try to parse and format.

slfmt.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.1.2"
+version       = "0.2.3"
 author        = "Jonathan Bernard"
 description   = "Small utility to pretty-print strucutured logs."
 license       = "MIT"
@@ -10,5 +10,5 @@ bin           = @["slfmt"]
 
 # Dependencies
 
-requires @["nim >= 2.2.0", "docopt"]
-requires "timeutils"
+requires @["nim >= 2.2.0", "docopt >= 0.7.1"]
+requires @["timeutils", "zero_functional"]

src/slfmt.nim

@@ -1,10 +1,10 @@
 import std/[json, options, sequtils, streams, strutils, terminal, times]
-import timeutils
-import docopt
+import docopt, timeutils, zero_functional
 
 from std/logging import Level
+from std/sequtils import toSeq
 
-const VERSION = "0.1.2"
+const VERSION = "0.2.3"
 
 const USAGE = """Usage:
    slfmt [options]
@@ -12,6 +12,7 @@ const USAGE = """Usage:
 Options:
 
    -h, --help               Print this usage and help information
+   -c, --compact            Compact output
    -l, --log-level <lvl>    Only show log events at or above this level
    -n, --namespace <ns>     Only show log events from this namespace
 """
@@ -44,7 +45,7 @@ func decorate(
   result &= s & ansiResetCode
 
 
-proc formatField(name: string, value: JsonNode): string =
+proc fullFormatField(name: string, value: JsonNode): string =
   result = decorate(name, fgCyan) & ":" & " ".repeat(max(1, 10 - name.len))
 
   var strVal: string = ""
@@ -62,24 +63,62 @@ proc formatField(name: string, value: JsonNode): string =
       else: strVal = pretty(value)
 
   let valLines = splitLines(strVal)
-  if name.len > 10 or strVal.len + 16 > terminalWidth() or valLines.len > 1:
+  if name.len + strVal.len + 6 > terminalWidth() or valLines.len > 1:
     result &= "\n" & valLines.mapIt("  " & it).join("\n") & "\n"
   else: result &= strVal & "\n"
 
-proc prettyPrintFormat(logJson: JsonNode): string =
+proc fullFormat(logJson: JsonNode): string =
   result = '-'.repeat(terminalWidth()) & "\n"
 
   # Print the known fields in order first
   for f in fieldDisplayOrder:
     if logJson.hasKey(f):
-      result &= formatField(f, logJson[f])
+      result &= fullFormatField(f, logJson[f])
       logJson.delete(f)
 
   # Print the rest of the fields
-  for (key, val) in pairs(logJson): result &= formatField(key, val)
+  for (key, val) in pairs(logJson): result &= fullFormatField(key, val)
 
   result &= "\n"
 
+proc compactFormat(logJson: JsonNode): string =
+  let ts = parseIso8601(logJson["ts"].getStr).local.formatIso8601
+  var level = logJson["level"].getStr
+  if level == "ERROR": level = decorate(alignLeft(level, 7), fgRed)
+  elif level == "WARN": level = decorate(alignLeft(level, 7), fgYellow)
+  else: level = alignLeft(level, 7)
+
+  result = "$1 $2 $3: $4" % [
+    level,
+    decorate(alignLeft(ts[0..21], 23), fgBlue, {styleBright}),
+    decorate(logJson["scope"].getStr, fgGreen),
+    decorate(logJson["msg"].getStr, fgYellow)]
+
+  let restNodes = (toSeq(pairs(logJson))) -->
+    filter(not ["level", "scope", "ts", "msg"].contains(it[0]))
+
+  let restMsg = join(restNodes -->
+    map("$1: $2" % [
+      decorate(it[0], fgCyan),
+      if it[1].kind == JString: it[1].getStr
+      else: pretty(it[1]),
+      "  "]))
+
+  if restMsg.len + result.len + 2 < terminalWidth():
+    result &= "  " & restMsg
+  else:
+    var line = "  "
+    for (key, val) in restNodes:
+      let fieldVal =
+        if val.kind == JString: val.getStr
+        else: pretty(val)
+      let field = "$1: $2" % [decorate(key, fgCyan), fieldVal]
+      if line.len + field.len + 2 > terminalWidth():
+        result &= "\n  " & line
+        line = "  "
+      line &= field & "  "
+    result &= "\n  " & line
+
 proc parseLogLine(logLine: string): JsonNode =
   result = parseJson(logLine)
 
@@ -95,11 +134,15 @@ when isMainModule:
       if args["--namespace"]: some($args["--namespace"])
       else: none[string]()
 
+    let compact = args["--compact"]
+
     var line: string = ""
     let sin = newFileStream(stdin)
     while(sin.readLine(line)):
       try:
         let logJson = parseLogLine(line)
+        if logJson.kind != JObject:
+          raise newException(JsonParsingError, "Expected a JSON object")
 
         if logLevel.isSome and logJson.hasKey("level"):
           let lvl = parseLogLevel(logJson["level"].getStr)
@@ -108,7 +151,8 @@ when isMainModule:
         if namespace.isSome and logJson.hasKey("scope"):
           if not logJson["scope"].getStr.startsWith(namespace.get): continue
 
-        stdout.writeLine(prettyPrintFormat(logJson))
+        if compact: stdout.writeLine(compactFormat(logJson))
+        else: stdout.writeLine(fullFormat(logJson))
       except ValueError, JsonParsingError:
         stdout.writeLine(line)
   except: