PowerShell/test/powershell/Modules/Microsoft.PowerShell.Utility/ConvertFrom-Json.Tests.ps1

# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License.

function New-NestedJson {
    Param(
        [ValidateRange(1, 2048)]
        [int]
        $Depth
    )

    $nestedJson = "true"

    $Depth..1 | ForEach-Object {
        $nestedJson = '{"' + $_ + '":' + $nestedJson + '}'
    }

    return $nestedJson
}

function Count-ObjectDepth {
    Param([PSCustomObject] $InputObject)

    for ($i=1; $i -le 2048; $i++)
    {
        $InputObject = Select-Object -InputObject $InputObject -ExpandProperty $i
        if ($InputObject -eq $true)
        {
            return $i
        }
    }
}

Describe 'ConvertFrom-Json Unit Tests' -tags "CI" {

    BeforeAll {
        $testCasesWithAndWithoutAsHashtableSwitch = @(
            @{ AsHashtable = $true  }
            @{ AsHashtable = $false }
        )
    }

    It 'Can convert a single-line object with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        ('{"a" : "1"}' | ConvertFrom-Json -AsHashtable:$AsHashtable).a | Should -Be 1
    }

    It 'Can convert one string-per-object with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        $json = @('{"a" : "1"}', '{"a" : "x"}') | ConvertFrom-Json -AsHashtable:$AsHashtable
        $json.Count | Should -Be 2
        $json[1].a | Should -Be 'x'
        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
    }

    It 'Can convert multi-line object with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        $json = @('{"a" :', '"x"}') | ConvertFrom-Json -AsHashtable:$AsHashtable
        $json.a | Should -Be 'x'
        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
    }

    It 'Can convert an object with Newtonsoft.Json metadata properties with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        $id = 13
        $type = 'Calendar.Months.December'
        $ref = 1989

        $json = '{"$id":' + $id + ', "$type":"' + $type + '", "$ref":' + $ref + '}' | ConvertFrom-Json -AsHashtable:$AsHashtable

        $json.'$id' | Should -Be $id
        $json.'$type' | Should -Be $type
        $json.'$ref' | Should -Be $ref

        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
    }

    It 'Can convert an object of depth 1024 by default with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        $nestedJson = New-NestedJson -Depth 1024

        $json = $nestedJson | ConvertFrom-Json -AsHashtable:$AsHashtable

        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
        else
        {
            $json | Should -BeOfType PSCustomObject
        }
    }

    It 'Fails to convert an object of depth higher than 1024 by default with AsHashtable switch set to <AsHashtable>' -TestCases $testCasesWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable)
        $nestedJson = New-NestedJson -Depth 1025

        { $nestedJson | ConvertFrom-Json -AsHashtable:$AsHashtable } |
            Should -Throw -ErrorId "System.ArgumentException,Microsoft.PowerShell.Commands.ConvertFromJsonCommand"
    }

    It 'Can convert null' {
        'null' | ConvertFrom-Json | Should -Be $null
        $out = '[1, null, 2]' | ConvertFrom-Json
        $out.Length | Should -Be 3

        # can't compare directly to array as Pester doesn't handle the $null
        $out[0] | Should -Be 1
        $out[1] | Should -Be $null
        $out[2] | Should -Be 2
    }
}

Describe 'ConvertFrom-Json -Depth Tests' -tags "Feature" {

    BeforeAll {
        $testCasesJsonDepthWithAndWithoutAsHashtableSwitch = @(
            @{ Depth = 2;    AsHashtable = $true  }
            @{ Depth = 2;    AsHashtable = $false }
            @{ Depth = 200;  AsHashtable = $true  }
            @{ Depth = 200;  AsHashtable = $false }
            @{ Depth = 2000; AsHashtable = $true  }
            @{ Depth = 2000; AsHashtable = $false }
        )
    }

    It 'Can convert an object with depth less than Depth param set to <Depth> and AsHashtable switch set to <AsHashtable>' -TestCases $testCasesJsonDepthWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable, $Depth)
        $nestedJson = New-NestedJson -Depth ($Depth - 1)

        $json = $nestedJson | ConvertFrom-Json -AsHashtable:$AsHashtable -Depth $Depth

        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
        else
        {
            $json | Should -BeOfType PSCustomObject
        }

        (Count-ObjectDepth -InputObject $json) | Should -Be ($Depth - 1)
    }

    It 'Can convert an object with depth equal to Depth param set to <Depth> and AsHashtable switch set to <AsHashtable>' -TestCases $testCasesJsonDepthWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable, $Depth)
        $nestedJson = New-NestedJson -Depth:$Depth

        $json = $nestedJson | ConvertFrom-Json -AsHashtable:$AsHashtable -Depth $Depth

        if ($AsHashtable)
        {
            $json | Should -BeOfType Hashtable
        }
        else
        {
            $json | Should -BeOfType PSCustomObject
        }

        (Count-ObjectDepth -InputObject $json) | Should -Be $Depth
    }

    It 'Fails to convert an object with greater depth than Depth param set to <Depth> and AsHashtable switch set to <AsHashtable>' -TestCases $testCasesJsonDepthWithAndWithoutAsHashtableSwitch {
        Param($AsHashtable, $Depth)
        $nestedJson = New-NestedJson -Depth ($Depth + 1)

        { $nestedJson | ConvertFrom-Json -AsHashtable:$AsHashtable -Depth $Depth } |
            Should -Throw -ErrorId "System.ArgumentException,Microsoft.PowerShell.Commands.ConvertFromJsonCommand"
    }
}