断点

【Breakpoints】

• setBreakpoint()，sb()：在当前行设置断点
• setBreakpoint(line)、sb(line)：在特定行设置断点
• setBreakpoint('fn()')、sb(...)：在函数体的第一条语句上设置断点
• setBreakpoint('script.js', 1)，sb(...)：在 script.js 的第一行设置断点
• setBreakpoint('script.js', 1, 'num < 4')，sb(...)：在 script.js 的第一行设置条件断点，只有当 num < 4 计算结果为 true 时才会中断
• clearBreakpoint('script.js', 1)，cb(...)：清除 script.js 第 1 行的断点

也可以在尚未加载的文件（模块）中设置断点：

【It is also possible to set a breakpoint in a file (module) that is not loaded yet:】

$ node inspect main.js
< Debugger listening on ws://127.0.0.1:9229/48a5b28a-550c-471b-b5e1-d13dd7165df9
< For help, see: https://nodejs.cn/docs/inspector
<
connecting to 127.0.0.1:9229 ... ok
< Debugger attached.
<
Break on start in main.js:1
> 1 const mod = require('./mod.js');
  2 mod.hello();
  3 mod.hello();
debug> setBreakpoint('mod.js', 22)
Warning: script 'mod.js' was not loaded yet.
debug> c
break in mod.js:22
 20 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 21
>22 exports.hello = function() {
 23   return 'hello from module';
 24 };
debug> 拷贝

也可以设置一个条件断点，仅当给定表达式计算结果为 true 时才会中断：

【It is also possible to set a conditional breakpoint that only breaks when a given expression evaluates to true:】

$ node inspect main.js
< Debugger listening on ws://127.0.0.1:9229/ce24daa8-3816-44d4-b8ab-8273c8a66d35
< For help, see: https://nodejs.cn/docs/inspector
<
connecting to 127.0.0.1:9229 ... ok
< Debugger attached.
Break on start in main.js:7
  5 }
  6
> 7 addOne(10);
  8 addOne(-1);
  9
debug> setBreakpoint('main.js', 4, 'num < 0')
  1 'use strict';
  2
  3 function addOne(num) {
> 4   return num + 1;
  5 }
  6
  7 addOne(10);
  8 addOne(-1);
  9
debug> cont
break in main.js:4
  2
  3 function addOne(num) {
> 4   return num + 1;
  5 }
  6
debug> exec('num')
-1
debug> 拷贝