lix/tests/functional/pure-eval.sh

source common.sh

clearStore

nix eval --expr 'assert 1 + 2 == 3; true'

[[ $(nix eval --impure --expr 'builtins.readFile ./pure-eval.sh') =~ clearStore ]]

missingImpureErrorMsg=$(! nix eval --expr 'builtins.readFile ./pure-eval.sh' 2>&1)

echo "$missingImpureErrorMsg" | grepQuiet -- --impure || \
    fail "The error message should mention the “--impure” flag to unblock users"

[[ $(nix eval --expr 'builtins.pathExists ./pure-eval.sh') == false ]] || \
    fail "Calling 'pathExists' on a non-authorised path should return false"

(! nix eval --expr builtins.currentTime)
(! nix eval --expr builtins.currentSystem)

(! nix-instantiate --pure-eval ./simple.nix)

[[ $(nix eval --impure --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; })).x") == 123 ]]
(! nix eval --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; })).x")
nix eval --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; sha256 = \"$(nix hash file pure-eval.nix --type sha256)\"; })).x"

rm -rf $TEST_ROOT/eval-out
nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ x = "foo" + "bar"; y = { z = "bla"; }; }'
[[ $(cat $TEST_ROOT/eval-out/x) = foobar ]]
[[ $(cat $TEST_ROOT/eval-out/y/z) = bla ]]

rm -rf $TEST_ROOT/eval-out
(! nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ "." = "bla"; }')

(! nix eval --expr '~/foo')
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced. 2018-01-16 18:50:38 +01:00			`source common.sh`

			`clearStore`

nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables. 2019-11-27 00:05:30 +01:00			`nix eval --expr 'assert 1 + 2 == 3; true'`
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced. 2018-01-16 18:50:38 +01:00
nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables. 2019-11-27 00:05:30 +01:00			`[[ $(nix eval --impure --expr 'builtins.readFile ./pure-eval.sh') =~ clearStore ]]`
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced. 2018-01-16 18:50:38 +01:00
Fix the error when accessing a forbidden path in pure eval If we’re in pure eval mode, then tell that in the error message rather than (wrongly) speaking about restricted mode. Fix https://github.com/NixOS/nix/issues/5611 2021-11-25 14:48:01 +01:00			`missingImpureErrorMsg=$(! nix eval --expr 'builtins.readFile ./pure-eval.sh' 2>&1)`

Harden tests' bash Use `set -u` and `set -o pipefail` to catch accidental mistakes and failures more strongly. - `set -u` catches the use of undefined variables - `set -o pipefail` catches failures (like `set -e`) earlier in the pipeline. This makes the tests a bit more robust. It is nice to read code not worrying about these spurious success paths (via uncaught) errors undermining the tests. Indeed, I caught some bugs doing this. There are a few tests where we run a command that should fail, and then search its output to make sure the failure message is one that we expect. Before, since the `grep` was the last command in the pipeline the exit code of those failing programs was silently ignored. Now with `set -o pipefail` it won't be, and we have to do something so the expected failure doesn't accidentally fail the test. To do that we use `expect` and a new `expectStderr` to check for the exact failing exit code. See the comments on each for why. `grep -q` is replaced with `grepQuiet`, see the comments on that function for why. `grep -v` when we just want the exit code is replaced with `grepInverse, see the comments on that function for why. `grep -q -v` together is, surprise surprise, replaced with `grepQuietInverse`, which is both combined. Co-authored-by: Robert Hensing <roberth@users.noreply.github.com> 2021-12-09 16:26:46 +01:00			`echo "$missingImpureErrorMsg" \| grepQuiet -- --impure \|\| \`
Fix the error when accessing a forbidden path in pure eval If we’re in pure eval mode, then tell that in the error message rather than (wrongly) speaking about restricted mode. Fix https://github.com/NixOS/nix/issues/5611 2021-11-25 14:48:01 +01:00			`fail "The error message should mention the “--impure” flag to unblock users"`
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced. 2018-01-16 18:50:38 +01:00
Properly return false on `builtins.pathExists /someNonAllowedPath` Follow-up from https://github.com/NixOS/nix/pull/5807 to fix https://github.com/NixOS/nix/pull/5807#issuecomment-1000135394 2021-12-23 10:35:09 +01:00			`[[ $(nix eval --expr 'builtins.pathExists ./pure-eval.sh') == false ]] \|\| \`
			`fail "Calling 'pathExists' on a non-authorised path should return false"`

nix: Add --expr flag This replaces the '(...)' installable syntax, which is not very discoverable. The downside is that you can't have multiple expressions or mix expressions and other installables. 2019-11-27 00:05:30 +01:00			`(! nix eval --expr builtins.currentTime)`
			`(! nix eval --expr builtins.currentSystem)`
Add pure evaluation mode In this mode, the following restrictions apply: * The builtins currentTime, currentSystem and storePath throw an error. * $NIX_PATH and -I are ignored. * fetchGit and fetchMercurial require a revision hash. * fetchurl and fetchTarball require a sha256 attribute. * No file system access is allowed outside of the paths returned by fetch{Git,Mercurial,url,Tarball}. Thus 'nix build -f ./foo.nix' is not allowed. Thus, the evaluation result is completely reproducible from the command line arguments. E.g. nix build --pure-eval '( let nix = fetchGit { url = https://github.com/NixOS/nixpkgs.git; rev = "9c927de4b179a6dd210dd88d34bda8af4b575680"; }; nixpkgs = fetchGit { url = https://github.com/NixOS/nixpkgs.git; ref = "release-17.09"; rev = "66b4de79e3841530e6d9c6baf98702aa1f7124e4"; }; in (import (nix + "/release.nix") { inherit nix nixpkgs; }).build.x86_64-linux )' The goal is to enable completely reproducible and traceable evaluation. For example, a NixOS configuration could be fully described by a single Git commit hash. 'nixos-rebuild' would do something like nix build --pure-eval '( (import (fetchGit { url = file:///my-nixos-config; rev = "..."; })).system ') where the Git repository /my-nixos-config would use further fetchGit calls or Git externals to fetch Nixpkgs and whatever other dependencies it has. Either way, the commit hash would uniquely identify the NixOS configuration and allow it to reproduced. 2018-01-16 18:50:38 +01:00
			`(! nix-instantiate --pure-eval ./simple.nix)`

treewide: Stop using URL literals They must die Change-Id: Ibe2b1818b21d98ec1a68836d01d5dad729b8c501 2024-08-10 15:12:26 +02:00			`[[ $(nix eval --impure --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; })).x") == 123 ]]`
			`(! nix eval --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; })).x")`
			`nix eval --expr "(import (builtins.fetchurl { url = \"file://$(pwd)/pure-eval.nix\"; sha256 = \"$(nix hash file pure-eval.nix --type sha256)\"; })).x"`
nix eval: Add option to write a directory This is useful for generating the nix manpages, but it may have other applications (like generating configuration files without a Nix store). 2020-12-02 21:25:32 +01:00
			`rm -rf $TEST_ROOT/eval-out`
			`nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ x = "foo" + "bar"; y = { z = "bla"; }; }'`
			`[[ $(cat $TEST_ROOT/eval-out/x) = foobar ]]`
			`[[ $(cat $TEST_ROOT/eval-out/y/z) = bla ]]`

			`rm -rf $TEST_ROOT/eval-out`
			`(! nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ "." = "bla"; }')`
Forbid the tilde expansion in pure eval mode Fix #6684 2022-06-21 14:08:18 +02:00
			`(! nix eval --expr '~/foo')`