use proptest to check invariants

Cargo.lock

@@ -25,6 +25,29 @@ dependencies = [
  "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bit-set"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-vec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bitflags"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "byteorder"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "c2-chacha"
 version = "0.2.3"
@@ -53,6 +76,14 @@ dependencies = [
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "cloudabi"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "failure"
 version = "0.1.6"
@@ -73,6 +104,16 @@ dependencies = [
  "synstructure 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fnv"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "getrandom"
 version = "0.1.13"
@@ -88,6 +129,11 @@ name = "itoa"
 version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "libc"
 version = "0.2.66"
@@ -116,6 +162,7 @@ version = "0.1.0"
 dependencies = [
  "chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.44 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -133,6 +180,30 @@ dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "proptest"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rusty-fork 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quick-error"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "quote"
 version = "1.0.2"
@@ -141,6 +212,24 @@ dependencies = [
  "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand"
 version = "0.7.2"
@@ -153,6 +242,15 @@ dependencies = [
  "rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_chacha"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.2.1"
@@ -162,6 +260,19 @@ dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "rand_core"
 version = "0.5.1"
@@ -170,6 +281,14 @@ dependencies = [
  "getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_hc"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rand_hc"
 version = "0.2.0"
@@ -178,16 +297,96 @@ dependencies = [
  "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand_isaac"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_jitter"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_os"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_pcg"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_xorshift"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "regex-syntax"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "remove_dir_all"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "rusty-fork"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wait-timeout 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "ryu"
 version = "1.0.2"
@@ -242,6 +441,19 @@ dependencies = [
  "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "tempfile"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "time"
 version = "0.1.42"
@@ -266,6 +478,14 @@ dependencies = [
  "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "wait-timeout"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "wasi"
 version = "0.7.0"
@@ -294,35 +514,61 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
 "checksum backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)" = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
 "checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
+"checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
+"checksum bit-vec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f59bbe95d4e52a6398ec21238d31577f2b28a9d86807f06ca59d191d8440d0bb"
+"checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
 "checksum c2-chacha 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "214238caa1bf3a496ec3392968969cab8549f96ff30652c9e56885329315f6bb"
 "checksum cc 1.0.48 (registry+https://github.com/rust-lang/crates.io-index)" = "f52a465a666ca3d838ebbf08b241383421412fe7ebb463527bba275526d89f76"
 "checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 "checksum chrono 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "31850b4a4d6bae316f7a09e691c944c28299298837edc0a03f755618c23cbc01"
+"checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "f8273f13c977665c5db7eb2b99ae520952fe5ac831ae4cd09d80c4c7042b5ed9"
 "checksum failure_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0bc225b78e0391e4b8683440bf2e63c2deeeb2ce5189eab46e2b68c6d3725d08"
+"checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 "checksum getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "e7db7ca94ed4cd01190ceee0d8a8052f08a247aa1b469a7f68c6a3b71afcf407"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
+"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 "checksum libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)" = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"
 "checksum num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)" = "b85e541ef8255f6cf42bbfe4ef361305c6c135d10919ecc26126c4e5ae94bc09"
 "checksum num-traits 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c81ffc11c212fa327657cb19dd85eb7419e163b5b076bede2bdb5c974c07e4"
 "checksum ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
 "checksum proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "9c9e470a8dc4aeae2dee2f335e8f533e2d4b347e1434e5671afc49b054592f27"
+"checksum proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)" = "cf147e022eacf0c8a054ab864914a7602618adba841d800a9a9868a5237a529f"
+"checksum quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9274b940887ce9addde99c4eee6b5c44cc494b182b97e73dc8ffdcb3397fd3f0"
 "checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+"checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
 "checksum rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3ae1b169243eaf61759b8475a998f0a385e42042370f3a7dbaf35246eacc8412"
+"checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
 "checksum rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
 "checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+"checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
 "checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+"checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
+"checksum rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "1166d5c91dc97b88d1decc3285bb0a99ed84b05cfd0bc2341bdf2d43fc41e39b"
+"checksum rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
+"checksum rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
+"checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
+"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
+"checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
 "checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783"
+"checksum rusty-fork 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3dd93264e10c577503e926bd1430193eeb5d21b059148910082245309b424fae"
 "checksum ryu 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "bfa8506c1de11c9c4e4c38863ccbe02a305c8188e85a05a784c9e11e1c3910c8"
 "checksum serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)" = "414115f25f818d7dfccec8ee535d76949ae78584fc4f79a6f45a904bf8ab4449"
 "checksum serde_derive 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)" = "128f9e303a5a29922045a830221b8f78ec74a5f544944f3d5984f8ec3895ef64"
 "checksum serde_json 1.0.44 (registry+https://github.com/rust-lang/crates.io-index)" = "48c575e0cc52bdd09b47f330f646cf59afc586e9c4e3ccd6fc1f625b8ea1dad7"
 "checksum syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)" = "dff0acdb207ae2fe6d5976617f887eb1e35a2ba52c13c7234c790960cdad9238"
 "checksum synstructure 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)" = "67656ea1dc1b41b1451851562ea232ec2e5a80242139f7e679ceccfb5d61f545"
+"checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
 "checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
 "checksum uuid 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9fde2f6a4bea1d6e007c4ad38c6839fa71cbb63b6dbf5b595aa38dc9b1093c11"
+"checksum wait-timeout 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9f200f5b12eb75f8c1ed65abd4b2db8a6e1b138a20de009dacee265a2498f3f6"
 "checksum wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b89c3ce4ce14bdc6fb6beaf9ec7928ca331de5df7e5ea278375642a2f478570d"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"

Cargo.toml

@@ -11,3 +11,6 @@ uuid = { version = "0.8.1", features = ["serde", "v4"] }
 serde_json = "1.0"
 chrono = "0.4.10"
 failure = {version = "0.1.5", features = ["derive"] }
+
+[dev-dependencies]
+proptest = "0.9.4"

src/lib.rs

@@ -4,3 +4,6 @@
 mod errors;
 mod operation;
 mod taskdb;
+
+pub use operation::Operation;
+pub use taskdb::DB;

src/operation.rs

@@ -72,6 +72,7 @@ impl Operation {
                     (None, Some(operation2))
                 } else if timestamp1 > timestamp2 {
                     // prefer the later modification
+                    //(Some(operation1), None)
                     (Some(operation1), None)
                 } else {
                     // arbitrarily resolve in favor of the first operation
@@ -89,6 +90,10 @@ impl Operation {
 mod test {
     use super::*;
     use crate::taskdb::DB;
+    use chrono::{Duration, Utc};
+
+    // note that `tests/operation_transform_invariant.rs` tests the transform function quite
+    // thoroughly, so this testing is light.
 
     fn test_transform(
         o1: Operation,
@@ -102,14 +107,14 @@ mod test {
         // check that the two operation sequences have the same effect, enforcing the invariant of
         // the transform function.
         let mut db1 = DB::new();
-        db1.apply(o1).unwrap();
+        db1.apply(o1);
         if let Some(o) = o2p {
-            db1.apply(o).unwrap();
+            db1.apply(o);
         }
         let mut db2 = DB::new();
-        db2.apply(o2).unwrap();
+        db2.apply(o2);
         if let Some(o) = o1p {
-            db2.apply(o).unwrap();
+            db2.apply(o);
         }
         assert_eq!(db1.tasks(), db2.tasks());
     }
@@ -120,10 +125,100 @@ mod test {
         let uuid2 = Uuid::new_v4();
 
         test_transform(
-            Operation::Create { uuid: uuid1 },
+            Create { uuid: uuid1 },
-            Operation::Create { uuid: uuid2 },
+            Create { uuid: uuid2 },
-            Some(Operation::Create { uuid: uuid1 }),
+            Some(Create { uuid: uuid1 }),
-            Some(Operation::Create { uuid: uuid2 }),
+            Some(Create { uuid: uuid2 }),
+        );
+    }
+
+    #[test]
+    fn test_related_updates_different_props() {
+        let uuid = Uuid::new_v4();
+        let timestamp = Utc::now();
+
+        test_transform(
+            Update {
+                uuid,
+                property: "abc".into(),
+                value: true.into(),
+                timestamp,
+            },
+            Update {
+                uuid,
+                property: "def".into(),
+                value: false.into(),
+                timestamp,
+            },
+            Some(Update {
+                uuid,
+                property: "abc".into(),
+                value: true.into(),
+                timestamp,
+            }),
+            Some(Update {
+                uuid,
+                property: "def".into(),
+                value: false.into(),
+                timestamp,
+            }),
+        );
+    }
+
+    #[test]
+    fn test_related_updates_same_prop() {
+        let uuid = Uuid::new_v4();
+        let timestamp1 = Utc::now();
+        let timestamp2 = timestamp1 + Duration::seconds(10);
+
+        test_transform(
+            Update {
+                uuid,
+                property: "abc".into(),
+                value: true.into(),
+                timestamp: timestamp1,
+            },
+            Update {
+                uuid,
+                property: "abc".into(),
+                value: false.into(),
+                timestamp: timestamp2,
+            },
+            None,
+            Some(Update {
+                uuid,
+                property: "abc".into(),
+                value: false.into(),
+                timestamp: timestamp2,
+            }),
+        );
+    }
+
+    #[test]
+    fn test_related_updates_same_prop_same_time() {
+        let uuid = Uuid::new_v4();
+        let timestamp = Utc::now();
+
+        test_transform(
+            Update {
+                uuid,
+                property: "abc".into(),
+                value: true.into(),
+                timestamp,
+            },
+            Update {
+                uuid,
+                property: "abc".into(),
+                value: false.into(),
+                timestamp,
+            },
+            Some(Update {
+                uuid,
+                property: "abc".into(),
+                value: true.into(),
+                timestamp,
+            }),
+            None,
         );
     }
 }

src/taskdb.rs

@@ -1,11 +1,10 @@
-use crate::errors::Error;
 use crate::operation::Operation;
 use serde_json::Value;
 use std::collections::hash_map::Entry;
 use std::collections::HashMap;
 use uuid::Uuid;
 
-#[derive(PartialEq, Debug)]
+#[derive(PartialEq, Debug, Clone)]
 pub struct DB {
     // The current state, with all pending operations applied
     tasks: HashMap<Uuid, HashMap<String, Value>>,
@@ -30,18 +29,15 @@ impl DB {
     }
 
     /// Apply an operation to the DB.  Aside from synchronization operations, this
-    /// is the only way to modify the DB.
+    /// is the only way to modify the DB.  In cases where an operation does not
-    pub fn apply(&mut self, op: Operation) -> Result<(), Error> {
+    /// make sense, this function will ignore the operation.
+    pub fn apply(&mut self, op: Operation) {
         match op {
             Operation::Create { uuid } => {
-                match self.tasks.entry(uuid) {
+                // insert if the task does not already exist
-                    Entry::Occupied(_) => {
+                if let ent @ Entry::Vacant(_) = self.tasks.entry(uuid) {
-                        return Err(Error::DBError(format!("Task {} already exists", uuid)));
+                    ent.or_insert(HashMap::new());
-                    }
+                }
-                    ent @ Entry::Vacant(_) => {
-                        ent.or_insert(HashMap::new());
-                    }
-                };
             }
             Operation::Update {
                 ref uuid,
@@ -49,18 +45,13 @@ impl DB {
                 ref value,
                 timestamp: _,
             } => {
-                match self.tasks.get_mut(uuid) {
+                // update if this task exists, otherwise ignore
-                    Some(task) => {
+                if let Some(task) = self.tasks.get_mut(uuid) {
-                        task.insert(property.clone(), value.clone());
+                    task.insert(property.clone(), value.clone());
-                    }
+                }
-                    None => {
-                        return Err(Error::DBError(format!("Task {} does not exist", uuid)));
-                    }
-                };
             }
         };
         self.operations.push(op);
-        Ok(())
     }
 
     /// Get a read-only reference to the underlying set of tasks.
@@ -82,7 +73,7 @@ mod tests {
         let mut db = DB::new();
         let uuid = Uuid::new_v4();
         let op = Operation::Create { uuid };
-        db.apply(op.clone()).unwrap();
+        db.apply(op.clone());
 
         let mut exp = HashMap::new();
         exp.insert(uuid, HashMap::new());
@@ -94,11 +85,14 @@ mod tests {
     fn test_apply_create_exists() {
         let mut db = DB::new();
         let uuid = Uuid::new_v4();
-        db.apply(Operation::Create { uuid }).unwrap();
+        let op = Operation::Create { uuid };
-        assert_eq!(
+        db.apply(op.clone());
-            db.apply(Operation::Create { uuid }),
+        db.apply(op.clone());
-            Err(Error::DBError(format!("Task {} already exists", uuid)))
+
-        );
+        let mut exp = HashMap::new();
+        exp.insert(uuid, HashMap::new());
+        assert_eq!(db.tasks(), &exp);
+        assert_eq!(db.operations, vec![op.clone(), op]);
     }
 
     #[test]
@@ -106,14 +100,14 @@ mod tests {
         let mut db = DB::new();
         let uuid = Uuid::new_v4();
         let op1 = Operation::Create { uuid };
-        db.apply(op1.clone()).unwrap();
+        db.apply(op1.clone());
         let op2 = Operation::Update {
             uuid,
             property: String::from("title"),
             value: Value::from("\"my task\""),
             timestamp: Utc::now(),
         };
-        db.apply(op2.clone()).unwrap();
+        db.apply(op2.clone());
 
         let mut exp = HashMap::new();
         let mut task = HashMap::new();
@@ -127,14 +121,15 @@ mod tests {
     fn test_apply_update_does_not_exist() {
         let mut db = DB::new();
         let uuid = Uuid::new_v4();
-        assert_eq!(
+        let op = Operation::Update {
-            db.apply(Operation::Update {
+            uuid,
-                uuid,
+            property: String::from("title"),
-                property: String::from("title"),
+            value: Value::from("\"my task\""),
-                value: Value::from("\"my task\""),
+            timestamp: Utc::now(),
-                timestamp: Utc::now(),
+        };
-            }),
+        db.apply(op.clone());
-            Err(Error::DBError(format!("Task {} does not exist", uuid)))
+
-        );
+        assert_eq!(db.tasks(), &HashMap::new());
+        assert_eq!(db.operations, vec![op]);
     }
 }

tests/operation_transform_invariant.rs

@@ -0,0 +1,60 @@
+use chrono::Utc;
+use ot::Operation;
+use ot::DB;
+use proptest::prelude::*;
+use uuid::Uuid;
+
+fn uuid_strategy() -> impl Strategy<Value = Uuid> {
+    prop_oneof![
+        Just(Uuid::parse_str("83a2f9ef-f455-4195-b92e-a54c161eebfc").unwrap()),
+        Just(Uuid::parse_str("56e0be07-c61f-494c-a54c-bdcfdd52d2a7").unwrap()),
+        Just(Uuid::parse_str("4b7ed904-f7b0-4293-8a10-ad452422c7b3").unwrap()),
+        Just(Uuid::parse_str("9bdd0546-07c8-4e1f-a9bc-9d6299f4773b").unwrap()),
+    ]
+}
+
+fn operation_strategy() -> impl Strategy<Value = Operation> {
+    prop_oneof![
+        uuid_strategy().prop_map(|uuid| Operation::Create { uuid }),
+        (uuid_strategy(), "(title|project|status)").prop_map(|(uuid, property)| {
+            Operation::Update {
+                uuid,
+                property,
+                value: true.into(),
+                timestamp: Utc::now(),
+            }
+        }),
+    ]
+}
+
+proptest! {
+    #[test]
+    fn transform_invariant_holds(o1 in operation_strategy(), o2 in operation_strategy()) {
+        let (o1p, o2p) = Operation::transform(o1.clone(), o2.clone());
+
+        // check that the two operation sequences have the same effect, enforcing the invariant of
+        // the transform function.  This needs some care as if either of the operations is
+        // an Update then we must ensure the task already exists in the DB.
+        let mut db1 = DB::new();
+
+        if let Operation::Update{ ref uuid, .. } = o1 {
+            db1.apply(Operation::Create{uuid: uuid.clone()});
+        }
+
+        if let Operation::Update{ ref uuid, .. } = o2 {
+            db1.apply(Operation::Create{uuid: uuid.clone()});
+        }
+
+        let mut db2 = db1.clone();
+
+        db1.apply(o1);
+        if let Some(o) = o2p {
+            db1.apply(o);
+        }
+        db2.apply(o2);
+        if let Some(o) = o1p {
+            db2.apply(o);
+        }
+        assert_eq!(db1.tasks(), db2.tasks());
+    }
+}