[xfile] prep for fuzzing

go.mod

@@ -6,16 +6,18 @@ require (
 	github.com/BurntSushi/toml v0.3.1
 	github.com/davecgh/go-spew v1.1.1
 	github.com/go-chi/chi v1.5.1
+	github.com/go-redis/redis/v8 v8.11.0 // indirect
 	github.com/imdario/mergo v0.3.9
+	github.com/konsorten/go-windows-terminal-sequences v1.0.3 // indirect
 	github.com/logrusorgru/aurora v2.0.3+incompatible
 	github.com/machinebox/progress v0.2.0
 	github.com/pelletier/go-toml v1.7.0
 	github.com/pkg/errors v0.9.1
-	github.com/seatgeek/logrus-gelf-formatter v0.0.0-20180829220724-ce23ecb3f367
-	github.com/sirupsen/logrus v1.6.0
+	github.com/seatgeek/logrus-gelf-formatter v0.0.0-20210414080842-5b05eb8ff761
+	github.com/sirupsen/logrus v1.8.1
 	github.com/stretchr/testify v1.5.1
 	golang.org/x/net v0.0.0-20210119194325-5f4716e94777
 	golang.org/x/time v0.0.0-20201208040808-7e3f01d25324
 	gopkg.in/h2non/gock.v1 v1.0.15
-	gopkg.in/yaml.v2 v2.2.8
+	gopkg.in/yaml.v2 v2.4.0
 )

go.sum

@@ -1,12 +1,32 @@
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
+github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/go-chi/chi v1.5.1 h1:kfTK3Cxd/dkMu/rKs5ZceWYp+t5CtiE7vmaTv3LjC6w=
 github.com/go-chi/chi v1.5.1/go.mod h1:REp24E+25iKvxgeTfHmdUoL5x15kBiDBlnIl5bCwe2k=
+github.com/go-redis/redis/v8 v8.11.0 h1:O1Td0mQ8UFChQ3N9zFQqo6kTU2cJ+/it88gDB+zg0wo=
+github.com/go-redis/redis/v8 v8.11.0/go.mod h1:DLomh7y2e3ggQXQLd1YgmvIfecPJoFl7WU5SOQ/r06M=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.4.0-rc.1/go.mod h1:ceaxUfeHdC40wWswd/P6IGgMaK3YpKi5j83Wpe3EHw8=
+github.com/golang/protobuf v1.4.0-rc.1.0.20200221234624-67d41d38c208/go.mod h1:xKAWHe0F5eneWXFV3EuXVDTCmh+JuBKY0li0aMyXATA=
+github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrUpVNzEA03Pprs=
+github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
+github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
+github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 h1:2VTzZjLZBgl62/EtslCrtky5vbi9dd7HrQPQIx6wqiw=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542/go.mod h1:Ow0tF8D4Kplbc8s8sSb3V2oUCygFHVp8gC3Dn6U4MNI=
+github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/imdario/mergo v0.3.9 h1:UauaLniWCFHWd+Jp9oCEkTBj8VO/9DKg3PV3VCNMDIg=
 github.com/imdario/mergo v0.3.9/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
@@ -17,6 +37,13 @@ github.com/machinebox/progress v0.2.0 h1:7z8+w32Gy1v8S6VvDoOPPBah3nLqdKjr3GUly18
 github.com/machinebox/progress v0.2.0/go.mod h1:hl4FywxSjfmkmCrersGhmJH7KwuKl+Ueq9BXkOny+iE=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy/FJl/rCYT0+EuS8+Z0z4=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
+github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
+github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
+github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
+github.com/onsi/ginkgo v1.15.0/go.mod h1:hF8qUzuuC8DJGygJH3726JnCZX4MYbRB8yFfISqnKUg=
+github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
+github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
+github.com/onsi/gomega v1.10.5/go.mod h1:gza4q3jKQJijlu05nKWRCW/GavJumGt8aNRxWg7mt48=
 github.com/pelletier/go-toml v1.7.0 h1:7utD74fnzVc/cpcyy8sjrlFr5vYpypUixARcHIMIGuI=
 github.com/pelletier/go-toml v1.7.0/go.mod h1:vwGMzjaWMwyfHwgIBhI2YUM4fB6nL6lVAvS1LBMMhTE=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -25,27 +52,75 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/seatgeek/logrus-gelf-formatter v0.0.0-20180829220724-ce23ecb3f367 h1:kjJVIlsZ+29dcgTtHVJDtK7ykrf7e1tW/63UvYSCEJw=
 github.com/seatgeek/logrus-gelf-formatter v0.0.0-20180829220724-ce23ecb3f367/go.mod h1:/THDZYi7F/BsVEcYzYPqdcWFQ+1C2InkawTKfLOAnzg=
+github.com/seatgeek/logrus-gelf-formatter v0.0.0-20210414080842-5b05eb8ff761 h1:0b8DF5kR0PhRoRXDiEEdzrgBc8UqVY4JWLkQJCRsLME=
+github.com/seatgeek/logrus-gelf-formatter v0.0.0-20210414080842-5b05eb8ff761/go.mod h1:/THDZYi7F/BsVEcYzYPqdcWFQ+1C2InkawTKfLOAnzg=
 github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
+github.com/sirupsen/logrus v1.8.1 h1:dJKuHgqk1NNQlqoA6BTlM1Wf9DOH3NBjQyu0h9+AZZE=
+github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20201202161906-c7110b5ffcbb/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777 h1:003p0dJM77cxMSyCPFphvZf/Y5/NXf5fzg6ufd1/Oew=
 golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210112080510-489259a85091 h1:DMyOG0U+gKfu8JZzg2UQe9MeaC1X+xQWlAKcRnjxjCw=
+golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/time v0.0.0-20201208040808-7e3f01d25324 h1:Hir2P/De0WpUhtrKGGjvSb2YxUgyZ7EFOSLIcSSpiwE=
 golang.org/x/time v0.0.0-20201208040808-7e3f01d25324/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20201224043029-2b0845dc783e/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
+google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
+google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
+google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
+google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
+google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/h2non/gock.v1 v1.0.15 h1:SzLqcIlb/fDfg7UvukMpNcWsu7sI5tWwL+KCATZqks0=
 gopkg.in/h2non/gock.v1 v1.0.15/go.mod h1:sX4zAkdYX1TRGJ2JY156cFspQn4yRWn6p9EMdODlynE=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=

xfile/copy.go

@@ -0,0 +1,50 @@
+package fileutil
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+)
+
+// Copy will copy the file from src to dst, the paths have to be absolute to
+// ensure consistent behavior.
+func Copy(src string, dst string) (err error) {
+	if !filepath.IsAbs(src) || !filepath.IsAbs(dst) {
+		return fmt.Errorf("can't copy src to dst paths not abosulte between src: %s and dst: %s", src, dst)
+	}
+
+	srcStat, err := os.Stat(src)
+	if err != nil {
+		return errors.Wrap(err, "failed to copy file")
+	}
+
+	if !srcStat.Mode().IsRegular() {
+		return fmt.Errorf("failed to copy file %s not a regular file", src)
+	}
+
+	srcFile, err := os.Open(src)
+	if err != nil {
+		return errors.Wrap(err, "failed to open file to copy")
+	}
+	defer func() {
+		err = srcFile.Close()
+	}()
+
+	dstFile, err := os.Create(dst)
+	if err != nil {
+		return errors.Wrapf(err, "failed to create file to copy to for %s", src)
+	}
+	defer func() {
+		err = dstFile.Close()
+	}()
+
+	_, err = io.Copy(dstFile, srcFile)
+	if err != nil {
+		return errors.Wrapf(err, "failed to copy file src: %s dst: %s", src, dstFile.Name())
+	}
+
+	return err
+}

xfile/create.go

@@ -0,0 +1,103 @@
+package fileutil
+
+import (
+	"crypto/rand"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+)
+
+// Specify the number of bytes you want to be different when create partial
+// matching files.
+const numOfDiffBytes = 4
+
+// Create will create a file in a specific dir, for the specific size. The
+// data inside of file is completely random.
+func Create(dir string, size int) (fileName string, err error) {
+	tmpFile, err := ioutil.TempFile(dir, "")
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to create tmp file inside of %s", dir)
+	}
+	defer func() {
+		err = tmpFile.Close()
+	}()
+
+	var fileContent = make([]byte, size)
+	_, err = rand.Read(fileContent)
+	if err != nil {
+		return "", errors.Wrap(err, "failed to create random data for file")
+	}
+
+	_, err = tmpFile.Write(fileContent)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to write random data to file %s", tmpFile.Name())
+	}
+
+	return tmpFile.Name(), err
+}
+
+// useful for fuzzing
+
+// CreatePartialMatch will create two files that have the same size and the
+// first few bytes but the final 4 bytes of the file are different. The 4 extra
+// bytes are included into the specified size.
+func CreatePartialMatch(dir string, size int) ([]string, error) {
+	if !filepath.IsAbs(dir) {
+		return nil, fmt.Errorf("cannot append to file, path %s is not absolute", dir)
+	}
+
+	// Create the identical files.
+	originalFile, err := Create(dir, size-numOfDiffBytes)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to create file inside %s", dir)
+	}
+
+	var cpFile = fmt.Sprintf("%s_partial", originalFile)
+
+	err = Copy(originalFile, cpFile)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to copy file to %s", dir)
+	}
+
+	err = appendToFile(originalFile, numOfDiffBytes)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to append random data to %s", originalFile)
+	}
+
+	err = appendToFile(cpFile, numOfDiffBytes)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to append random data to %s", originalFile)
+	}
+
+	return []string{originalFile, cpFile}, nil
+}
+
+func appendToFile(path string, size int) (err error) {
+	if !filepath.IsAbs(path) {
+		return fmt.Errorf("cannot append to file, path is not absolute: %s", path)
+	}
+
+	f, err := os.OpenFile(path, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return errors.Wrapf(err, "failed to open file %s", path)
+	}
+	defer func() {
+		err = f.Close()
+	}()
+
+	var appendData = make([]byte, size)
+
+	_, err = rand.Read(appendData)
+	if err != nil {
+		return errors.Wrapf(err, "failed to create random data for file")
+	}
+
+	if _, err := f.Write(appendData); err != nil {
+		return errors.Wrapf(err, "failed to append data to file %s", path)
+	}
+
+	return err
+}