if condition

    goal:
    - add condition support
    supported:
      true: ["1", "t", "T", "TRUE", "true", "True"]
      false: ["0", "f", "F", "FALSE", "false", "False"]
    tasks:
    - name: task
      task:
      - func: shell
        do:
        - echo "hello, world"
        if: "true"
      - func: shell
        do:
        - echo "hello, world"
        if: "false"
      - func: shell
        do:
        - echo "hello, world"
        if: "FALSE"
      - func: shell
        desc: |
          note that for one step, there will be only one
          return, which will be the last do cmd
          in this case, since the step3 exit code is 0
          the whole step will have the return code of 0
          if you need to use the exit code of the step
          you need to consider to reduce the number of do cmds
          or put it to last step, this is not a bug
          this is a feature
        flags:
        - ignoreError
        do:
        - echo "step1"
        - echo "step2" |grep notexist
        - echo "step3"
      - func: shell
        do:
        - echo "hello, world"
      - func: shell
        dvars:
        - name: last_task_succeeded
          value: "{{eq .last_result.Code 0}}"
          flags: [vvvv]
        do:
        - echo "check last step"
        - echo "{{.last_result|toJson}}"
        - echo "{{.last_result|toPrettyJson}}"
        - echo "{{eq .last_result.Code 0}}"
        if: "{{eq .last_result.Code 0}}"
      - func: shell
        flags:
        - ignoreError
        do:
        - echo "step1"
        - echo "step2" |grep notexist
      - func: shell
        do:
        - echo "check last step"
        - echo "{{.last_result|toJson}}"
        - echo "{{.last_result|toPrettyJson}}"
        if: "{{eq .last_result.Code 0}}"
      - func: shell
        vars:
          student:
            name: peter
            sex: male
            age: 23
        dvars:
        - name: condition
          value: '{{eq .student.sex "male"}}'
          flags: [vvvv]
        do:
        - echo "simple dvar as condition"
        if: "{{.condition}}"
      - func: shell
        vars:
          student:
            name: peter
            sex: male
            age: 23
        dvars:
        - name: condition
          value: '{{and (ge .student.age 18) (eq .student.sex "male") }}'
          flags: [vvvv]
        do:
        - echo "complicated dvar evaluation as condition"
        if: "{{.condition}}"
      - func: shell
        vars:
          student:
            name: peter
            sex: male
            age: 23
        dvars:
        - name: condition
          value: |
            {{- with .student -}}
            {{and (ge .age 18) (eq .sex "male") }}
            {{- end -}}
          flags: [vvvv]
        do:
        - echo "a even more complicated condition but more readable"
        if: "{{.condition}}"
      - func: shell
        vars:
          student:
            name: peter
            sex: male
            age: 23
        do:
        - echo "a complicated condition without dvar"
        if: |
          {{- with .student -}}
          {{and (ge .age 18) (eq .sex "male") }}
          {{- end -}}
      - func: cmd
        desc: |
          show that complicated arg needs to be quoted using ()
          otherwise it will cause gt to be confused
        vars:
          doc: hello
        do:
        - name: print
          cmd: '{{ gt (.doc|len) 1 }}'
      - func: cmd
        vars:
          doc: hello
        do:
        - name: print
          cmd: '{{ gt (.doc|len) 1 }}'
        if: '{{gt (.doc|len) 0}}'
    

    loading [Config]:  ./tests/functests/upconfig.yml
    Main config:
                 Version -> 1.0.0
                  RefDir -> ./tests/functests
                 WorkDir -> cwd
              AbsWorkDir -> /up_project/up
                TaskFile -> c0054
                 Verbose -> vvv
              ModuleName -> self
               ShellType -> /bin/sh
           MaxCallLayers -> 8
                 Timeout -> 3600000
     MaxModuelCallLayers -> 256
               EntryTask -> task
      ModRepoUsernameRef -> 
      ModRepoPasswordRef -> 
    work dir: /up_project/up
    -exec task: task
    loading [Task]:  ./tests/functests/c0054
    module: [self], instance id: [dev], exec profile: []
    profile -  envVars:
    
    (*core.Cache)({
    })
    
    Task1: [task ==> task:  ]
    -Step1:
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 0
    })
    
    cmd( 1):
    echo "hello, world"
    
    -
    hello, world
    
    -
     .. ok
    . ok
    -Step2:
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"hello, world\"",
        Code: 0,
        Output: "hello, world",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0
    })
    
    condition failed, skip executing step 
    
    -Step3:
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)(<nil>),
      "up_runtime_task_layer_number": 0
    })
    
    condition failed, skip executing step 
    
    -Step4: [
    note that for one step, there will be only one
    return, which will be the last do cmd
    in this case, since the step3 exit code is 0
    the whole step will have the return code of 0
    if you need to use the exit code of the step
    you need to consider to reduce the number of do cmds
    or put it to last step, this is not a bug
    this is a feature
    ]
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)(<nil>),
      "up_runtime_task_layer_number": 0
    })
    
    cmd( 1):
    echo "step1"
    
    -
    step1
    
    -
     .. ok
    cmd( 2):
    echo "step2" |grep notexist
    
    -
    
    -
     .. failed(suppressed if it is not the last step)
    cmd( 3):
    echo "step3"
    
    -
    step3
    
    -
     .. ok
    . ok
    -Step5:
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"step3\"",
        Code: 0,
        Output: "step3",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0
    })
    
    cmd( 1):
    echo "hello, world"
    
    -
    hello, world
    
    -
     .. ok
    . ok
    -Step6:
    dvar> last_task_succeeded:
    "true"
    
    -
    true
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"hello, world\"",
        Code: 0,
        Output: "hello, world",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0,
      "last_task_succeeded": "true"
    })
    
    cmd( 1):
    echo "check last step"
    
    -
    check last step
    
    -
     .. ok
    cmd( 2):
    echo "{{.last_result|toJson}}"
    
    -
    {Cmd:echo "hello, world",Code:0,Output:hello, world,ErrMsg:}
    
    -
     .. ok
    cmd( 3):
    echo "{{.last_result|toPrettyJson}}"
    
    -
    {
      Cmd: echo "hello, world",
      Code: 0,
      Output: hello, world,
      ErrMsg: 
    }
    
    -
     .. ok
    cmd( 4):
    echo "{{eq .last_result.Code 0}}"
    
    -
    true
    
    -
     .. ok
    . ok
    -Step7:
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 0,
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"true\"",
        Code: 0,
        Output: "true",
        ErrMsg: ""
      })
    })
    
    cmd( 1):
    echo "step1"
    
    -
    step1
    
    -
     .. ok
    cmd( 2):
    echo "step2" |grep notexist
    
    -
    
    -
     .. failed(suppressed if it is not the last step)
     WARN: [ignoreError:] - [Error ignored!!!]
    -Step8:
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 0,
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"step2\" |grep notexist",
        Code: 1,
        Output: "",
        ErrMsg: "exit status 1"
      })
    })
    
    condition failed, skip executing step 
    
    -Step9:
    dvar> condition:
    "true"
    
    -
    true
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)(<nil>),
      "up_runtime_task_layer_number": 0,
      "student": {
        "sex": "male",
        "age": 23,
        "name": "peter"
      },
      "condition": "true"
    })
    
    cmd( 1):
    echo "simple dvar as condition"
    
    -
    simple dvar as condition
    
    -
     .. ok
    . ok
    -Step10:
    dvar> condition:
    "true"
    
    -
    true
    self: final context exec vars:
    
    (*core.Cache)({
      "condition": "true",
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"simple dvar as condition\"",
        Code: 0,
        Output: "simple dvar as condition",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0,
      "student": {
        "sex": "male",
        "age": 23,
        "name": "peter"
      }
    })
    
    cmd( 1):
    echo "complicated dvar evaluation as condition"
    
    -
    complicated dvar evaluation as condition
    
    -
     .. ok
    . ok
    -Step11:
    dvar> condition:
    "true"
    
    -
    true
    self: final context exec vars:
    
    (*core.Cache)({
      "student": {
        "name": "peter",
        "sex": "male",
        "age": 23
      },
      "condition": "true",
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"complicated dvar evaluation as condition\"",
        Code: 0,
        Output: "complicated dvar evaluation as condition",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0
    })
    
    cmd( 1):
    echo "a even more complicated condition but more readable"
    
    -
    a even more complicated condition but more readable
    
    -
     .. ok
    . ok
    -Step12:
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 0,
      "student": {
        "name": "peter",
        "sex": "male",
        "age": 23
      },
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"a even more complicated condition but more readable\"",
        Code: 0,
        Output: "a even more complicated condition but more readable",
        ErrMsg: ""
      })
    })
    
    cmd( 1):
    echo "a complicated condition without dvar"
    
    -
    a complicated condition without dvar
    
    -
     .. ok
    . ok
    -Step13: [
    show that complicated arg needs to be quoted using ()
    otherwise it will cause gt to be confused
    ]
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"a complicated condition without dvar\"",
        Code: 0,
        Output: "a complicated condition without dvar",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0,
      "doc": "hello"
    })
    
    ~SubStep1: [print:  ]
    true
    -Step14:
    self: final context exec vars:
    
    (*core.Cache)({
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"a complicated condition without dvar\"",
        Code: 0,
        Output: "a complicated condition without dvar",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0,
      "doc": "hello"
    })
    
    ~SubStep1: [print:  ]
    true