typescript - 在文件中创建计算类型的导出

Question

我想知道是否有可能给一个具有导出类型的文件，这些类型是否可以从泛型中提取到计算类型？

function example() {
  return {
    foo: 'hi',
    bar: true,
    baz: 1
  };
}

export type Signature = ReturnType<typeof example>;

对此:

export type Signature = {
    foo: string;
    bar: boolean;
    baz: number;
}

我不相信 tsc cli 会这样做，我不确定这个过程会被称为什么。 tsc 可以创建这个导出吗？
有没有第三方工具可以做到这一点？
我知道如何做到这一点的唯一方法是将鼠标悬停在 VSCode 中的变量上并复制计算类型，这仅在它很短时才有效，并且不会减弱......
我发现了其他一些对类似请求的引用:

Option to expand computed TypeScript types on hover

Is it possible to display the full computed type of a typescript type/interface in VSCode (or elsewhere)

VS code how to show full typescript definition on mouse hover

Show full type in typescript type hover hint

Add full type hover popup to VS Code commands

Interactive Diagnostics

Answer 1

调查这个问题，而不复制 VSCode 的 hover.ts ，我发现这个问题的一个，如果不是唯一的，答案是:
从 tsserver 中提取悬停“quickinfo”
您需要将文件中的行和字符偏移量传达给服务器。应该可以用abstract syntax tree (AST)在 .ts为了那个原因。我用 bash 写了一个客户端。下面附上，它支持从列计算字符偏移量(如 VSCode 状态栏中所示)。来自源代码运行的日志和“签名”一词上的文档位置紧随其后，结尾非常接近您想要的提取。

$ (prepared=('open -s #.ts -i file' 'quickinfo -s #.ts -i file -n 9 -i line -n 20 -i _column_')&&. $(which tsssh))
ts < open -s #.ts -i file
{"seq": 1, "type": "request", "command": "open", "arguments": {"file": "#.ts"}}
ts < quickinfo -s #.ts -i file -n 9 -i line -n 20 -i _column_
{"seq": 1, "type": "request", "command": "quickinfo", "arguments": {"file": "#.ts", "line": 9, "offset": 19}}
event #0
event: typingsInstallerPid
body: {"pid": 65341}
response #0 (1)
command: quickinfo
body: {"kind": "type", "kindModifiers": "export", "start": {"line": 9, "offset": 13}, "end": {"line": 9, "offset": 22}, "displayString": "type Signature = {\n    foo: string;\n    bar: boolean;\n    baz: number;\n}", "documentation": "", "tags": []}
displayString: type Signature = {
    foo: string;
    bar: boolean;
    baz: number;
}

https://github.com/Microsoft/TypeScript/wiki/Standalone-Server-%28tsserver%29. 的快速而肮脏的客户端.

严重依赖先决条件 http://kmkeen.com/jshon/ ，以及兼容的 bash 和 gawk，而 tput 和 tee 可以被剪掉我猜..

在 macOS 10.13.6 版本 上开发5.0.16 bash -O cmdhist -O lithist与 macports 和其他各种商店..

注意:您需要通过发送空命令行来手动轮询事件/响应。使用 kill -sigint 退出，通常是 ctrl+C..

在本地仓库中运行，如 tsserver=./node_modules/typescript/bin/tsserver tsssh ..

使用 histfile= path/to/tsssh 禁用历史记录.多个“准备”可以指定为 (prepared=("first" ... "last")&&. path/to/tsssh)

#!/usr/bin/env bash
( # Quick and dirty client for https://github.com/Microsoft/TypeScript/wiki/Standalone-Server-%28tsserver%29..
  # Relies heavily on prerequisite http://kmkeen.com/jshon/, and compatible bash and gawk, while tput and tee could be cut out I guess..
  # Developed on macOS 10.13.6 in version 5.0.16 `bash -O cmdhist -O lithist` with macports, and various other shopt..
  # NB: You need to poll event/response manually by sending empty commandlines. Exit with kill -sigint , typically ctrl+C..
  # Run in local repo like `tsserver=./node_modules/typescript/bin/tsserver tsssh`..
  # Disable history with `histfile='' path/to/tsssh`. Multiple "prepared" can be specified as `(prepared=("first" ... "last")&&. path/to/tsssh)`
  # Copyright 2020 Viktor Bergquist (vike2000@gmail.com), license https://creativecommons.org/licenses/by-sa/4.0/
  HISTFILE=${histfile-.tsssh_history} &&
  { ((\!-( x = xtrace )))||set -x ;} && ((!errexit))||set -e &&
  state()(set +x;tput setaf $1;echo "${*:2}";tput sgr0;((\!-x))||set -x) >&2 && trap 'state 1 $?: "$BASH_COMMAND"' err &&
  [[ ! $HISTFILE ]]||{ h=$HISTSIZE&&HISTSIZE=1&&set -o history&&HISTSIZE=$h&&history -s ''&&{ history -r "$HISTFILE"||:;};}&&
  coproc ts (${tsserver:-tsserver}) &&set -o pipefail&&command sleep 1 &&
  show(){ set +x; f=$1&&shift && i=$(cat) && declare -n n&&for n;do
      n=$(((\!-x))||set -x; jshon <<<"$i" -e "${!n}" $f);((e=$?)) || echo "${!n}: $n"; done; ((\!-x))||set -x; return $e;} &&
  extract(){ show "$@";} >/dev/null &&
  compact()( "$@"|gawk -vORS= '{sub("^\\s+",!m[0]?"":" ")}1;{match($0,",$",m)}END{printf"\n"}') &&
  function check(){ while {
        read -rt.1 -d$'\r' h&&[[ $h =~ Content-Length:\ ([0-9]+) ]]&&read -r$t -N3&&read -r$t -N$((${BASH_REMATCH[1]}-1)) a;} <&${ts[0]};do
      #set +x;echo 'ts > '"$a";((\!-x))||set -x
                <<<"$a" extract -u type seq &&case $type in
      (   event)state 2 $type \#$seq
                <<<"$a" show -u event ;;&
      (response)<<<"$a" extract -u success request_seq&&case $success in
        ( false)state 1 $type \#$seq "($request_seq)"
                <<<"$a" show -u command message ;;
        (  true)state 2 $type \#$seq "($request_seq)"
                <<<"$a" show -u command message metadata 2>/dev/null ;;
        (     *)state 1 "unknown success: $success" ;esac ;&
      (   event)<<<"$a" compact show '' body ;! [[ $type = response && $success = true ]]||case $command in
        (     *)<<<"$a" extract '' body ;;&
        ( quickinfo) <<< "$body" show -u displayString ;esac ;;
      (       *)state 1 "unknown type: $type" ;esac ;done;} &&
  seq=0 && for p in ${!prepared[@]} -1;do for fd in <(echo "${prepared[p]}") 0;do fd="${fd##*/}"; (((p<0)!=(0<fd)))||continue
      while check <&-; set +x; read -p 'ts < ' -era Q; do
        ((\!${#Q[*]}))&&{ tput -S<<<$'cuu1\nel'
          ((\!-x))||set -x;} ||
        { ((\!-x))||set -x
          history -s "${Q[*]}"&&{ [[ ! $HISTFILE ]]||{ [[ ! -a $HISTFILE ]]&&history -w "$HISTFILE"||history -a "$HISTFILE";};} &&
          d=$(compact jshon <<<{} -n$((++seq)) -i seq -s request -i type -s "$Q" -i command -n {} "${Q[@]:1}" -i arguments)
          A=$(compact jshon <<<{} "${Q[@]:1}")
          ! <<<"$A" extract -u file line _column_ 2>/dev/null ||
          { o=$(gawk -vT="${tabs:-4}" -vC="$_column_" FNR=="$line"'{
              t=-1;for(o=0;o<=length();o++){t++;if("\t"==substr($0,o,1)){t+=T-1;t-=t%T}if(t>=C)break}print o-1
              }' "$file") &&
            d=$(<<<"$d" compact jshon -e arguments -d _column_ -n "$o" -i offset -p);}
          tee   <<<"$d" /dev/stderr >&${ts[1]};}
        done<&$fd;done;done;set +x;echo bye) #ts < eg: reload -s index.ts -i file ^M quickinfo -s index.ts -i file -n 4 -i line -n 7 -i _column_

有了您所有问题的良好引用，您肯定知道可以使用 "compilerOptions":{"noErrorTruncation":true} 来防止您提到的某些“线索”。在 tsconfig.json :)
在这些引用文献的末尾，我可以补充说还有一个 Interactive Diagnostics PR 31384 (draft)希望:)
目前，我将在相关问答 How can I see the full expanded contract of a Typescript type? 中研究有趣的实用程序类型