Fix #19 #52; Evaluate defaultValueDesc and defaultValue in help message

confutils.nim

@@ -50,6 +50,7 @@ type
     terminalWidth: int
     namesWidth: int
     flags: set[HelpFlag]
+    defaultValueDescs: seq[string]
 
   CmdInfo = ref object
     name: string
@@ -74,7 +75,6 @@ type
     idx: int
     flags: set[OptFlag]
     hasDefault: bool
-    defaultInHelpText: string
     obsoleteMsg: string
     case kind: OptKind
     of Discriminator:
@@ -194,6 +194,12 @@ template flushOutputAndQuit(exitCode: int) =
   flushOutput
   quit exitCode
 
+func defaultValueDesc(appInfo: HelpAppInfo, optIdx: int): string =
+  if optIdx == -1:
+    ""
+  else:
+    appInfo.defaultValueDescs[optIdx]
+
 func helpOptDesc(appInfo: HelpAppInfo): string =
   result = "Show this help message and exit"
   if appInfo.hasDebugOpts:
@@ -367,7 +373,7 @@ proc describeInvocation(
       let cliArg = "<" & arg.name & ">"
       helpOutput fgArg, styleBright, cliArg
       helpOutput padding(cliArg, appInfo.namesWidth)
-      help.writeDesc appInfo, arg.desc, arg.defaultInHelpText
+      help.writeDesc appInfo, arg.desc, appInfo.defaultValueDesc(arg.idx)
       help.writeLongDesc appInfo, arg.longDesc
       helpOutput "\p"
 
@@ -410,7 +416,7 @@ proc describeOptionsList(
     if opt.desc.len > 0:
       help.writeDesc appInfo,
                       opt.desc.replace("%t", opt.typename),
-                      opt.defaultInHelpText
+                      appInfo.defaultValueDesc(opt.idx)
       help.writeLongDesc appInfo, opt.longDesc
 
     helpOutput "\p"
@@ -445,14 +451,16 @@ proc describeOptions(
       let helpOpt = OptInfo(
         kind: CliSwitch,
         name: "help",
-        desc: helpOptDesc(appInfo)
+        desc: helpOptDesc(appInfo),
+        idx: -1
       )
       describeOptionsList(help, [helpOpt], appInfo, excl)
       if appInfo.hasVersion:
         let versionOpt = OptInfo(
           kind: CliSwitch,
           name: "version",
-          desc: "Show program's version and exit"
+          desc: "Show program's version and exit",
+          idx: -1
         )
         describeOptionsList(help, [versionOpt], appInfo, excl)
 
@@ -828,6 +836,20 @@ proc generateFieldSetters(RecordType: NimNode): NimNode =
       defaultValue = field.readPragma"defaultValue"
       completerName = ident($field.name & "Complete")
       isFieldDiscriminator = newLit field.isDiscriminator
+      defaultValueDesc = field.readPragma"defaultValueDesc"
+      defaultValueHelp =
+        if defaultValueDesc != nil:
+          defaultValueDesc
+        elif defaultValue != nil:
+          defaultValue
+        else:
+          newLit("")
+      defaultValueHelpRepr =
+        if defaultValueDesc == nil and defaultValue != nil:
+          newLit(repr defaultValue)
+        else:
+          newLit("")
+      defaultValueHelpName = ident($field.name & "DefaultValueHelp")
 
     if defaultValue == nil:
       defaultValue = newCall(makeDefaultValue, newTree(nnkTypeOfExpr, configField))
@@ -838,9 +860,11 @@ proc generateFieldSetters(RecordType: NimNode): NimNode =
 
     settersArray.add newTree(nnkTupleConstr,
                              newLit($paramName),
-                             setterName, completerName,
+                             setterName,
+                             completerName,
                              newCall(bindSym"requiresInput", fixedFieldType),
-                             newCall(bindSym"acceptsMultipleValues", fixedFieldType))
+                             newCall(bindSym"acceptsMultipleValues", fixedFieldType),
+                             defaultValueHelpName)
 
     result.add quote do:
       {.push hint[XCannotRaiseY]: off.}
@@ -870,6 +894,22 @@ proc generateFieldSetters(RecordType: NimNode): NimNode =
         else:
           setField(`configField`, val, `defaultValue`)
 
+      proc `defaultValueHelpName`(): string {.
+        nimcall
+        gcsafe
+        sideEffect
+        raises: []
+      .} =
+        # defaultValue can be `config.otherField` which won't compile
+        # `$` may not be defined for this type
+        when compiles($`defaultValueHelp`):
+          when typeof($`defaultValueHelp`) is string:
+            $`defaultValueHelp`
+          else:
+            `defaultValueHelpRepr`
+        else:
+          `defaultValueHelpRepr`
+
     result.add quote do:
       {.pop.}
 
@@ -901,11 +941,6 @@ func findPath(parent, node: CmdInfo): seq[CmdInfo] =
   doAssert validPath(result, parent, node)
   result.add parent
 
-func toText(n: NimNode): string =
-  if n == nil: ""
-  elif n.kind in {nnkStrLit..nnkTripleStrLit}: n.strVal
-  else: repr(n)
-
 func readPragmaFlags(field: FieldDescription): set[OptFlag] =
   result = {}
   if field.readPragma("hidden") != nil:
@@ -927,10 +962,6 @@ proc cmdInfoFromType(T: NimNode): CmdInfo =
     let
       isImplicitlySelectable = field.readPragma"implicitlySelectable" != nil
       defaultValue = field.readPragma"defaultValue"
-      defaultValueDesc = field.readPragma"defaultValueDesc"
-      defaultInHelp = if defaultValueDesc != nil: defaultValueDesc
-                      else: defaultValue
-      defaultInHelpText = toText(defaultInHelp)
       obsoleteMsg = field.readPragma"obsolete"
       separator = field.readPragma"separator"
       longDesc = field.readPragma"longDesc"
@@ -948,7 +979,6 @@ proc cmdInfoFromType(T: NimNode): CmdInfo =
                       name: $field.name,
                       flags: optFlags,
                       hasDefault: defaultValue != nil,
-                      defaultInHelpText: defaultInHelpText,
                       typename: field.typ.repr)
 
     if desc != nil: opt.desc = desc.strVal
@@ -1290,19 +1320,27 @@ proc loadImpl[C, SecondarySources](
 
       return
 
-  proc lazyHelpAppInfo(flags: set[HelpFlag]): HelpAppInfo =
+  proc lazyHelpAppInfo(flags: set[HelpFlag], defaultValueDescs: seq[string]): HelpAppInfo =
     HelpAppInfo(
       copyrightBanner: copyrightBanner,
       appInvocation: appInvocation(),
       terminalWidth: termWidth,
       hasVersion: version.len > 0,
-      flags: flags
+      flags: flags,
+      defaultValueDescs: defaultValueDescs
     )
 
+  template getDefaultValueDescs(): seq[string] =
+    var defaultValueDescs = newSeq[string](fieldSetters.len)
+    for i in 0 ..< fieldSetters.len:
+      defaultValueDescs[i] = fieldSetters[i][5]()
+    defaultValueDescs
+
   template processHelpAndVersionOptions(optKey, optVal: string) =
     let key = optKey
     if cmpIgnoreStyle(key, "help") == 0:
-      help.showHelp(lazyHelpAppInfo(optVal.toHelpFlags), activeCmds)
+      let defaultValueDescs = getDefaultValueDescs()
+      help.showHelp(lazyHelpAppInfo(optVal.toHelpFlags, defaultValueDescs), activeCmds)
     elif version.len > 0 and cmpIgnoreStyle(key, "version") == 0:
       help.helpOutput version, "\p"
       flushOutputAndQuit QuitSuccess

tests/help/snapshots/test_default_value_desc.txt

@@ -4,5 +4,18 @@ test_default_value_desc [OPTIONS]...
 
 The following options are available:
 
- --help      Show this help message and exit.
- --opt1      tcp port [=9000].
+ --help       Show this help message and exit.
+ --opt1       tcp port [=9000].
+ --opt2       tcp port 2 [=9000].
+ --opt3       const default value desc [=ok].
+ --opt4       literal default value desc [=ok].
+ --opt5       distinct string [=ok].
+ --opt6       no dollar func defined [=NoDollar("default")].
+ --opt7       no dollar func defined with default desc [=ok].
+ --opt8       runtime value [=ok].
+ --opt9       runtime value [=ok].
+ --opt10      runtime value [=ok concat].
+ --opt11      default value can raise but default desc won't [=ok].
+ --opt12      default is config.opt11 [=config.opt11].
+ --opt13      default is config.opt11 with default desc [=ok].
+ --opt14      default enum is TestEnum.OK [=OK].

tests/help/test_default_value_desc.nim

@@ -7,9 +7,46 @@
 # This file may not be copied, modified, or distributed except according to
 # those terms.
 
+import os
 import ../../confutils
 
 const defaultEth2TcpPort = 9000
+const defaultDescOverride = "ok"
+
+type TestEnum {.pure.} = enum
+  BAD
+  OK
+
+type DisString = distinct string
+type NoDollar = distinct string
+
+proc `$`(s: DisString): string =
+  # this should show in the help message
+  "ok"
+
+proc completeCmdArg(T: type DisString, val: string): seq[string] =
+  completeCmdArg(string, val)
+
+proc parseCmdArg(T: type DisString, s: string): T =
+  parseCmdArg(string, s).DisString
+
+proc completeCmdArg(T: type NoDollar, val: string): seq[string] =
+  completeCmdArg(string, val)
+
+proc parseCmdArg(T: type NoDollar, s: string): T =
+  parseCmdArg(string, s).NoDollar
+
+proc runtimeVal(): string =
+  # do something that's not available at comptime
+  {.cast(raises: []).}:
+    discard getCurrentProcessId()
+  "ok"
+
+proc canRaise(): string {.raises: [ValueError].} =
+  # do something that's not available at comptime
+  if false:
+    raise (ref ValueError)(msg: "never raised")
+  "bad"
 
 type
   TestConf = object
@@ -19,4 +56,76 @@ type
       desc: "tcp port"
       name: "opt1" }: int
 
+    opt2 {.
+      defaultValue: defaultEth2TcpPort
+      desc: "tcp port 2"
+      name: "opt2" }: int
+
+    opt3 {.
+      defaultValue: "bad"
+      defaultValueDesc: defaultDescOverride
+      desc: "const default value desc"
+      name: "opt3" }: string
+
+    opt4 {.
+      defaultValue: "bad"
+      defaultValueDesc: "ok"
+      desc: "literal default value desc"
+      name: "opt4" }: string
+
+    opt5 {.
+      defaultValue: DisString("bad")
+      desc: "distinct string"
+      name: "opt5" }: DisString
+
+    opt6 {.
+      defaultValue: NoDollar("default")
+      desc: "no dollar func defined"
+      name: "opt6" }: NoDollar
+
+    opt7 {.
+      defaultValue: NoDollar("bad")
+      defaultValueDesc: "ok"
+      desc: "no dollar func defined with default desc"
+      name: "opt7" }: NoDollar
+
+    opt8 {.
+      defaultValue: runtimeVal()
+      desc: "runtime value"
+      name: "opt8" }: string
+
+    opt9 {.
+      defaultValue: "bad"
+      defaultValueDesc: runtimeVal()
+      desc: "runtime value"
+      name: "opt9" }: string
+
+    opt10 {.
+      defaultValue: "bad"
+      defaultValueDesc: runtimeVal() & " concat"
+      desc: "runtime value"
+      name: "opt10" }: string
+
+    opt11 {.
+      defaultValue: canRaise()
+      defaultValueDesc: "ok"
+      desc: "default value can raise but default desc won't"
+      name: "opt11" }: string
+
+    opt12 {.
+      defaultValue: config.opt11
+      desc: "default is config.opt11"
+      name: "opt12" }: string
+
+    opt13 {.
+      defaultValue: config.opt11
+      defaultValueDesc: "ok"
+      desc: "default is config.opt11 with default desc"
+      name: "opt13" }: string
+
+    opt14 {.
+      defaultValue: TestEnum.OK
+      desc: "default enum is TestEnum.OK"
+      name: "opt14" }: TestEnum
+
 let c = TestConf.load(termWidth = int.high)