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IMPLEMENTS implementations
==========================

Implementation sections for workspaces
--------------------------------------

We'll use `$DATADIR/workspace` as the workspace directory that is used.

    IMPLEMENTS GIVEN no workspace
    true

    IMPLEMENTS GIVEN an empty workspace directory
    mkdir "$DATADIR/workspace"

    IMPLEMENTS GIVEN a non-empty workspace directory
    mkdir "$DATADIR/workspace"
    touch "$DATADIR/workspace/random-file"

We run `morph init` in two different ways: either the simple way,
letting yarn catch errors, or in a way that catches the error so
we can test it later in a THEN step.

    IMPLEMENTS WHEN the user (attempts to initialise|initialises) a workspace
    set init "$DATADIR/workspace"
    if [ $MATCH_1 == "initialises" ]; then run_morph "$@"
    else attempt_morph "$@"; fi

    IMPLEMENTS THEN morph failed
    case $(cat "$DATADIR/morph-exit") in
        0) die "Morph should have failed, but didn't. Unexpected success!" ;;
    esac

    IMPLEMENTS THEN morph succeeded
    case $(cat "$DATADIR/morph-exit") in
    0)  echo "Morph succeeded!"
        ;;
    *)  die "Morph should have succeeded, but didn't. Unexpected failure!"
        ;;
    esac

We need to check that a workspace creation worked. This requires the
directory to exist, and its `.morph` subdirectory to exist, and nothing
else.

    IMPLEMENTS THEN an empty workspace exists
    is_dir "$DATADIR/workspace"
    is_dir "$DATADIR/workspace/.morph"
    assert_equal $(ls -A "$DATADIR/workspace" | wc -l) 1

Tests for things other than `morph init` just want to have a workspace
created.

    IMPLEMENTS GIVEN a workspace
    run_morph init "$DATADIR/workspace"

Implementation sections related to a simulated Trove
----------------------------------------------------

Morph needs access to a Trove, i.e., a git server, in order to do certain
kinds of stuff. We simulate this by creating a set of git repositories
locally, which we'll tell Morph to access using `file:` URLs. Specifically,
we'll create a repository to hold system and stratum morphologies, and
another to hold a chunk.

    IMPLEMENTS GIVEN a git server

    # Create a directory for all the git repositories.
    mkdir "$DATADIR/gits"

    # Create a repo for the system and stratum morphologies.

    mkdir "$DATADIR/gits/morphs"

    arch=$(run_morph print-architecture)
    cat << EOF > "$DATADIR/gits/morphs/test-system.morph"
    name: test-system
    kind: system
    arch: $arch
    strata:
    -   name: test-stratum
        morph: test-stratum
    EOF

    cat << EOF > "$DATADIR/gits/morphs/test-stratum.morph"
    name: test-stratum
    kind: stratum
    chunks:
    -   name: test-chunk
        repo: test:test-chunk
        ref: master
        morph: test-chunk
        build-mode: test
        build-depends: []
    EOF

    run_in "$DATADIR/gits/morphs" git init .
    run_in "$DATADIR/gits/morphs" git add .
    run_in "$DATADIR/gits/morphs" git commit -m Initial.
    run_in "$DATADIR/gits/morphs" git tag -a "test-tag" -m "Tagging test-tag"

    # Create the chunk repository.

    mkdir "$DATADIR/gits/test-chunk"

    # To verify that chunk splitting works, we have a chunk that installs
    # dummy files in all the places that different kinds of files are
    # usually installed. e.g. executables in `/bin` and `/usr/bin`

    cat << 'EOF' > "$DATADIR/gits/test-chunk/test-chunk.morph"
    name: test-chunk
    kind: chunk
    build-system: manual

    # `install-commands` is a list of shell commands to run. Commands
    # may be on multiple lines, and indeed anything programmatic will
    # benefit from doing so. Arguably we could have just one command,
    # but it's split into multiple so that morph can inform us which
    # command failed without us having to include a lot of status
    # information in the command and look at the error message.

    install-commands:

    # It's important that we can test whether executables get
    # installed, so we install an empty script into `/usr/bin/test` and
    # `/usr/sbin/test`.

    # `install -D` will create the leading components for us, and install
    # defaults to creating the file with its executable bit set.

    # `install` needs a source file to install, but since we only care
    # that the file exists, rather than its contents, we can use /dev/null
    # as the source.

    - |
      for bindir in bin sbin; do
          install -D /dev/null "$DESTDIR/$PREFIX/$bindir/test"
      done

    # We need shared libraries too, sometimes they're libraries to support
    # the executables that a chunk provides, sometimes for other chunks.

    # Libraries can be found in a variety of places, hence why we install
    # them into lib, lib32 and lib64.

    # Shared libraries' file names start with lib and end with `.so`
    # for shared-object, with version numbers optionally suffixed.

    - |
      for libdir in lib lib32 lib64; do
          dirpath="$DESTDIR/$PREFIX/$libdir"
          install -D /dev/null "$dirpath/libtest.so"
          ln -s libtest.so "$dirpath/libtest.so.0"
          ln -s libtest.so.0 "$dirpath/libtest.so.0.0"
          ln -s libtest.so.0.0 "$dirpath/libtest.so.0.0.0"
      done

    # Shared objects aren't the only kind of library, some executable
    # binaries count as libraries, such as git's plumbing commands.

    # In some distributions they go into /lib, in others, and the default
    # autotools configuration, they go into /libexec.

    - |
      install -D /dev/null "$DESTDIR/$PREFIX/libexec/test-bin"

    # As well as run-time libraries, there's development files. For C
    # this is headers, which describe the API of the libraries, which
    # then use the shared objects, and other files which are needed
    # to build the executables, but aren't needed to run them, such as
    # static libraries.

    # Header files go into `include` and end with `.h`. They are not
    # executable, so the install command changes the permissions with the
    # `-m` option.

    - |
      install -D -m 644 /dev/null "$DESTDIR/$PREFIX/include/test.h"

    # `pkg-config` is a standard way to locate libraries and get the
    # compiler flags needed to build with the library. It's also used
    # for other configuration for packages that don't install binaries,
    # so as well as being found in `lib/pkgconfig`, it can be found in
    # `share/pkgconfig`, so we install dummy files to both.

    - |
      for pkgdir in lib lib32 lib64 share; do
          install -D -m 644 /dev/null \
              "$DESTDIR/$PREFIX/$pkgdir/pkgconfig/test.pc"
      done

    # Static libraries can be used to build static binaries, which don't
    # require their dependencies to be installed. They are typically in
    # the form of `.a` archive and `.la` libtool archives.

    - |
      for libdir in lib lib32 lib64; do
          for libname in libtest.a libtest.la; do
              install -D -m 644 /dev/null "$DESTDIR/$PREFIX/$libdir/$libname"
          done
      done

    # Packages may also install documentation, this comes in a variety
    # of formats, but info pages, man pages and html documentation are
    # the most common.

    - |
      for docfile in info/test.info.gz man/man3/test.3.gz doc/test/doc.html; do
          install -D -m 644 /dev/null "$DESTDIR/$PREFIX/share/$docfile"
      done

    # Locale covers translations, timezones, keyboard layouts etc. in
    # all manner of strange file formats and locations.

    # Locale provides various translations for specific messages.

    - |
      install -D -m 644 /dev/null \
          "$DESTDIR/$PREFIX/share/locale/en_GB/LC_MESSAGES/test.mo"

    # Internationalisation (i18n) includes character maps and other data
    # such as currency.

    - |
      for localefile in i18n/locales/en_GB charmaps/UTF-8.gz; do
          install -D -m 644 /dev/null "$DESTDIR/$PREFIX/share/$localefile"
      done

    # Timezones are another kind of localisation.

    - |
      install -D -m 644 /dev/null "$DESTDIR/$PREFIX/share/zoneinfo/UTC"

    # We also need a catch rule for everything that doesn't fit into
    # the above categories, so to test that, we create some files that
    # don't belong in one.

    - |
      for cfgfile in test.conf README; do
          install -D -m 644 /dev/null "$DESTDIR/etc/test.d/$cfgfile"
      done
    EOF

    run_in "$DATADIR/gits/test-chunk" git init .
    run_in "$DATADIR/gits/test-chunk" git add .
    run_in "$DATADIR/gits/test-chunk" git commit -m Initial.

    # Create the Morph configuration file so we can access the repos
    # using test:foo URL aliases.

    cat << EOF > "$DATADIR/morph.conf"
    [config]
    repo-alias = test=file://$DATADIR/gits/%s#file://$DATADIR/gits/%s
    cachedir = $DATADIR/cache
    tempdir = $DATADIR/tmp
    trove-host= []
    EOF

    mkdir "$DATADIR/cache"
    mkdir "$DATADIR/tmp"

We need a consistent value for the architecture in some tests, so we
have a morphology using the test architecture.

    IMPLEMENTS GIVEN a system called (\S+) for the test architecture in the git server

    cat << EOF > "$DATADIR/gits/test-chunk/stage1-chunk.morph"
    name: stage1-chunk
    kind: chunk
    build-system: dummy
    EOF

    run_in "$DATADIR/gits/test-chunk" git init .
    run_in "$DATADIR/gits/test-chunk" git add .
    run_in "$DATADIR/gits/test-chunk" git commit -m Initial.


    cat << EOF > "$DATADIR/gits/morphs/build-essential.morph"
    name: build-essential
    kind: stratum
    chunks:
    -   name: stage1-chunk
        repo: test:test-chunk
        ref: master
        morph: stage1-chunk
        build-mode: bootstrap
        build-depends: []
    EOF

    cat << EOF > "$DATADIR/gits/morphs/core.morph"
    name: core
    kind: stratum
    build-depends:
    - morph: build-essential
    chunks:
    -   name: test-chunk
        repo: test:test-chunk
        ref: master
        morph: test-chunk
        build-mode: test
        build-depends: []
    EOF

    cat << EOF > "$DATADIR/gits/morphs/$MATCH_1.morph"
    arch: testarch
    configuration-extensions: []
    description: A system called $MATCH_1 for test architecture
    kind: system
    name: $MATCH_1
    strata:
    -   name: build-essential
        morph: build-essential
    -   name: core
        morph: core
    EOF

    run_in "$DATADIR/gits/morphs" git add "build-essential.morph"
    run_in "$DATADIR/gits/morphs" git add "core.morph"
    run_in "$DATADIR/gits/morphs" git add "$MATCH_1.morph"
    run_in "$DATADIR/gits/morphs" git commit -m "Added $MATCH_1 and strata morphologies."

Morphologies need to support having a null ref, which means look for the
stratum in the same repository and ref. Testing this requires different
morphologies.

    IMPLEMENTS GIVEN null refs for local strata
    nullify_local_refs test:morphs master \
        "$DATADIR/gits/morphs/test-system.morph" \
        "$DATADIR/gits/morphs/test-stratum.morph"
    run_in "$DATADIR/gits/morphs" git add .
    run_in "$DATADIR/gits/morphs" git commit -m "Use null refs."


Implementation sections for system branch operations
----------------------------------------------------

Checkout out an existing system branch. We parameterise this so the
same phrase can be used to check out any system branch.

    IMPLEMENTS WHEN the user (attempts to check|checks) out the system (branch|tag) called (\S+)
    cd "$DATADIR/workspace"
    set checkout test:morphs "$MATCH_3"
    if [ $MATCH_1 == "checks" ]; then run_morph "$@"
    else attempt_morph "$@"; fi

Attempt to check out a system branch from a root that has no systems.

    IMPLEMENTS WHEN the user attempts to check out from a repository with no systems
    cd "$DATADIR/workspace"
    attempt_morph checkout test:test-chunk master

We also need to verify that a system branch has been checked out.

    IMPLEMENTS THEN the system branch (\S+) is checked out
    is_dir "$DATADIR/workspace/$MATCH_1/test:morphs"
    is_file "$DATADIR/workspace/$MATCH_1/test:morphs/test-system.morph"
    is_file "$DATADIR/workspace/$MATCH_1/test:morphs/test-stratum.morph"

We can create a new branch, off master.

    IMPLEMENTS WHEN the user (attempts to create|creates) a system branch called (\S+)
    cd "$DATADIR/workspace"
    set branch test:morphs "$MATCH_2"
    if [ $MATCH_1 == "creates"]; then run morph "$@"
    else attempt_morph "$@"; fi

We can create a new branch, off another system branch.

    IMPLEMENTS WHEN the user creates a system branch called (\S+), based on (\S+)
    cd "$DATADIR/workspace"
    run_morph branch test:morphs "$MATCH_1" "$MATCH_2"

Attempt to branch a system branch from a root that had no systems.

    IMPLEMENTS WHEN the user attempts to branch a repository with no systems
    cd "$DATADIR/workspace"
    attempt_morph branch test:test-chunk foo

Pushing all changes in a system branch checkout to the git server.

    IMPLEMENTS WHEN the user pushes the system branch called (\S+) to the git server
    # FIXME: For now, this is just the morphs checkout.
    run_in "$DATADIR/workspace/$MATCH_1/test:morphs" git push origin HEAD

Report workspace path.

    IMPLEMENTS WHEN the user reports the workspace from the directory (\S+)
    cd "$DATADIR/workspace/$MATCH_1"
    run_morph workspace > "$DATADIR/workspace-reported"

    IMPLEMENTS THEN the workspace is reported correctly
    assert_equal $(cat "$DATADIR/workspace-reported") "$DATADIR/workspace"

    IMPLEMENTS WHEN the user attempts to report the workspace from a non-workspace directory
    cd "$DATADIR"
    attempt_morph workspace

Report system branch name:

    IMPLEMENTS WHEN the user (attempts to report|reports) the system branch from the directory (\S+)
    cd "$DATADIR/workspace/$MATCH_2"
    set $DATADIR/system-branch.reported
    if [ $MATCH_1 == reports ]; then run_morph show-system-branch > "$@"
    else attempt_morph show-system-branch > "$@"; fi

    IMPLEMENTS THEN the system branch is reported as (.*)
    echo "$MATCH_1" > "$DATADIR/system-branch.actual"
    diff -u "$DATADIR/system-branch.actual" "$DATADIR/system-branch.reported"

Report system branch root repository.

    IMPLEMENTS WHEN the user (attempts to report|reports) the system branch root repository from the directory (.*)
    cd "$DATADIR/workspace/$MATCH_2"
    set $DATADIR/branch-root.reported
    if [ $MATCH_1 == "reports" ]; then run_morph show-branch-root > "$@"
    else attempt_morph show-branch-root > "$@"; fi

    IMPLEMENTS THEN the system branch root repository is reported as (.*)
    echo "$MATCH_1" > "$DATADIR/branch-root.actual"
    diff -u "$DATADIR/branch-root.actual" "$DATADIR/branch-root.reported"

Editing morphologies with `morph edit`.

    IMPLEMENTS THEN in branch (\S+), (system|stratum) (\S+) refs (\S+) in (\S+)
    if [ $MATCH_2 == system ]; then set strata; else set chunks; fi
    "$SRCDIR/scripts/yaml-extract" \
        "$DATADIR/workspace/$MATCH_1/test:morphs/$MATCH_3.morph" \
        $@ name="$MATCH_4" ref > "$DATADIR/ref.actual"
    echo "$MATCH_5" > "$DATADIR/ref.wanted"
    diff -u "$DATADIR/ref.wanted" "$DATADIR/ref.actual"

    IMPLEMENTS WHEN the user edits the stratum (\S+) in the system (\S+) in branch (\S+)
    cd "$DATADIR/workspace/$MATCH_3/test:morphs"
    run_morph edit "$MATCH_2" "$MATCH_1"

    IMPLEMENTS WHEN the user edits the chunk (\S+) in the stratum (\S+) in the system (\S+) in branch (\S+)
    cd "$DATADIR/workspace/$MATCH_4/test:morphs"
    run_morph edit "$MATCH_3" "$MATCH_2" "$MATCH_1"

    IMPLEMENTS THEN the edited chunk (\S+) has git branch (\S+)
    ls -l "$DATADIR/workspace/$MATCH_2"
    cd "$DATADIR/workspace/$MATCH_2/$MATCH_1"
    git branch | awk '$1 == "*" { print $2 }' > "$DATADIR/git-branch.actual"
    echo "$MATCH_2" > "$DATADIR/git-branch.wanted"
    diff -u "$DATADIR/git-branch.wanted" "$DATADIR/git-branch.actual"

    IMPLEMENTS WHEN the user edits the chunk (\S+) in the stratum (\S+) with no system specified in branch (\S+)
    cd "$DATADIR/workspace/$MATCH_3"
    attempt_morph edit "$MATCH_2" "$MATCH_1"

To produce buildable morphologies, we need them to be of the same
architecture as the machine doing the testing. This uses `morph
print-architecture` to get a value appropriate for morph.

    IMPLEMENTS WHEN the user creates an uncommitted system morphology called (\S+) for our architecture in system branch (\S+)
    arch=$(morph print-architecture)
    cat << EOF > "$DATADIR/workspace/$MATCH_2/test:morphs/$MATCH_1.morph"
    arch: $arch
    configuration-extensions: []
    description: A system called $MATCH_1 for architectures $arch
    kind: system
    name: $MATCH_1
    strata:
    -   name: test-stratum
        morph: test-stratum
    EOF

Reporting status of checked out repositories:

    IMPLEMENTS THEN morph reports no outstanding changes in (\S+)
    cd "$DATADIR/workspace/$MATCH_1"
    run_morph status > "$DATADIR/morph.stdout"
    grep '^No repos have outstanding changes.' "$DATADIR/morph.stdout"

    IMPLEMENTS THEN morph reports changes in (\S+) in (\S+) only
    cd "$DATADIR/workspace/$MATCH_1"
    run_morph status > "$DATADIR/morph.stdout"

    # morph status is expected to produce records like this:
    #    On branch GITBRANCH, root baserock:baserock/morphs
    #        GITREPO: uncommitted changes
    # We check thet GITREPO matches $MATCH_2.

    awk '/: uncommitted changes$/ { print substr($1,1,length($1)-1) }' \
        "$DATADIR/morph.stdout" > "$DATADIR/changed.actual"
    echo "$MATCH_2" > "$DATADIR/changed.wanted"
    diff -u "$DATADIR/changed.wanted" "$DATADIR/changed.actual"

    IMPLEMENTS THEN morph reports changes in (\S+) in (\S+) and (\S+)
    cd "$DATADIR/workspace/$MATCH_1"
    run_morph status > "$DATADIR/morph.stdout"
    echo "status morph.stdout:"
    cat "$DATADIR/morph.stdout"
    awk '/: uncommitted changes$/ { print substr($1,1,length($1)-1) }' \
        "$DATADIR/morph.stdout" | sort > "$DATADIR/changed.actual"
    (echo "$MATCH_2"; echo "$MATCH_3") | sort > "$DATADIR/changed.wanted"
    diff -u "$DATADIR/changed.wanted" "$DATADIR/changed.actual"

    IMPLEMENTS WHEN creating file (\S+) in (\S+) in branch (\S+)
    touch "$DATADIR/workspace/$MATCH_3/$MATCH_2/$MATCH_1"

    IMPLEMENTS WHEN adding file (\S+) in (\S+) in branch (\S+) to git
    cd "$DATADIR/workspace/$MATCH_3/$MATCH_2"
    git add "$MATCH_1"

    IMPLEMENTS WHEN committing changes in (\S+) in branch (\S+)
    cd "$DATADIR/workspace/$MATCH_2/$MATCH_1"
    git commit -a -m test-commit

Running shell command in each checked out repository:

    IMPLEMENTS WHEN running shell command in each repo in (\S+)
    cd "$DATADIR/workspace/$MATCH_1"
    run_morph foreach -- pwd > "$DATADIR/morph.stdout"

    IMPLEMENTS THEN morph ran command in (\S+) in (\S+)
    grep -Fx "$MATCH_1" "$DATADIR/morph.stdout"
    grep -Fx "$DATADIR/workspace/$MATCH_2/$MATCH_1" "$DATADIR/morph.stdout"

Petrification and unpetrification:

    IMPLEMENTS WHEN remembering all refs in (\S+)
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    list_refs *.morph > "$DATADIR/refs.remembered"

    IMPLEMENTS THEN (\S+) refs are as remembered
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"

    # FIXME: petrify/unpetrify doesn't work quite right at this time:
    # petrify can change a ref to a stratum to point at the system
    # branch, but does it without adding an unpetrify-ref, and so
    # unpetrify doesn't undo the change. We ignore this bug for the
    # time being, in order to make the test suite pass. When the
    # petrification code has been cleaned up to not be so hairy,
    # we'll fix the test and the code.
    #
    # We would like to verify the result like this:
    #
    #   list_refs *.morph > "$DATADIR/refs.now"
    #   diff -u "$DATADIR/refs.remembered" "$DATADIR/refs.now"
    #
    # However, due to the bug, we have to do it in a more complicated
    # manner.

    list_refs *.morph |
    while read filename ref
    do
        orig=$(awk -v "f=$filename" '$1 == f { print $2 }' \
            "$DATADIR/refs.remembered")
        if [ "$orig" != "$ref" ] && [ "$ref" != "$MATCH_1" ]
        then
            die "Un-petrified ref: $filename $ref (should be $orig)"
        fi
    done

    IMPLEMENTS WHEN petrifying (\S+)
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    run_morph petrify

    IMPLEMENTS WHEN unpetrifying (\S+)
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    run_morph unpetrify

    IMPLEMENTS THEN (\S+) is petrified
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    assert_morphologies_are_petrified "$MATCH_1" *.morph

    IMPLEMENTS THEN (\S+) is not petrified
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    ! assert_morphologies_are_petrified "$MATCH_1" *.morph

Tagging.

    IMPLEMENTS WHEN the user tags the system branch called (\S+) as (\S+)
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    set tag "$MATCH_2" -- -m "testing morph tagging"
    run_morph tag "$MATCH_2" -- -m "testing morph tagging"

    IMPLEMENTS WHEN the user attempts to tag the system branch called (\S+) as (\S+)
    cd "$DATADIR/workspace/$MATCH_1/test:morphs"
    attempt_morph tag "$MATCH_2" -- -m "testing morph tagging"

    IMPLEMENTS THEN morph tag (\S+) in (\S+) is an annotated git tag
    cd "$DATADIR/workspace/$MATCH_2/test:morphs"
    if git show "$MATCH_1" | head -n1 | grep -v '^tag '
    then
        die "git tag $MATCH_1 is not an annotated tag"
    fi

    IMPLEMENTS THEN morph tag (\S+) in (\S+) refers to a petrified commit
    cd "$DATADIR/workspace/$MATCH_2/test:morphs"
    git ls-tree "$MATCH_1" |
    awk '$NF ~ /\.morph$/ { print $NF }' |
    while read x
    do
        git cat-file blob "$MATCH_1:$x" > temptemptemp
        assert_morphologies_are_petrified "$MATCH_1" temptemptemp
    done

Generating a manifest.

    IMPLEMENTS GIVEN a system artifact
    mkdir "$DATADIR/hello_world"

    git init "$DATADIR/hello_world"
    touch "$DATADIR/hello_world/configure.ac"
    run_in "$DATADIR/hello_world" git add configure.ac
    run_in "$DATADIR/hello_world" git commit -m 'Add configure.ac'

    mkdir "$DATADIR/baserock"
    run_in "$DATADIR/hello_world" cat << EOF \
        > "$DATADIR/baserock/hello_world.meta"
    {
        "artifact-name": "hello_world",
        "cache-key":
           "ab8d00a80298a842446ce23507cea6b4d0e34c7ddfa05c67f460318b04d21308",
        "kind": "chunk",
        "morphology": "hello_world.morph",
        "original_ref": "$(run_in "$DATADIR/hello_world" git rev-parse HEAD)",
        "repo": "file://$DATADIR/hello_world",
        "repo-alias": "upstream:hello_world",
        "sha1": "$(run_in "$DATADIR/hello_world" git rev-parse HEAD)",
        "source-name": "hello_world"
    }
    EOF
    run_in "$DATADIR" tar -c baserock > "$DATADIR/artifact.tar"

    IMPLEMENTS WHEN morph generates a manifest
    run_morph generate-manifest "$DATADIR/artifact.tar" > "$DATADIR/manifest"

    IMPLEMENTS THEN the manifest is generated

    # Generated manifest should contain the name of the repository
    if ! grep -q hello_world "$DATADIR/manifest"; then
        die "Output isn't what we expect"
    fi

Implementation sections for building
====================================

    IMPLEMENTS WHEN the user (attempts to build|builds) the system (\S+) in branch (\S+)
    cd "$DATADIR/workspace/$MATCH_3"
    set build "$MATCH_2"
    if [ $MATCH_1 == "builds" ]; then run_morph "$@"
    else attempt_morph "$@"; fi

Implementation sections for cross-bootstraping
==============================================

    IMPLEMENTS THEN the user cross-bootstraps the system (\S+) in branch (\S+) of repo (\S+) to the arch (\S+)
    cd "$DATADIR/workspace/$MATCH_2"
    set -- cross-bootstrap "$MATCH_4" "$MATCH_3" "$MATCH_2" "$MATCH_1"
    run_morph "$@"

Implementation sections for deployment
======================================

Defaults are set in the cluster morphology, so we can deploy without
setting any extra parameters, but we also need to be able to override
them, so they can be added to the end of the implements section.

    IMPLEMENTS WHEN the user (attempts to deploy|deploys) the (system|cluster) (\S+) in branch (\S+)( with options (.*))?
    cd "$DATADIR/workspace/$MATCH_4"
    set -- deploy "$MATCH_3"
    if [ "$MATCH_5" != '' ]; then
        # eval used so word splitting in the text is preserved
        eval set -- '"$@"' $MATCH_6
    fi
    if [ $MATCH_1 == "deploys" ]; then run_morph "$@"
    else attempt_morph "$@"; fi

To successfully deploy systems, we need a cluster morphology. Since the
common case is to just have one system, we generate a stub morphology
with only the minimal information.

    IMPLEMENTS GIVEN a cluster called (\S+) for deploying only the (\S+) system as type (\S+) in system branch (\S+)
    name="$MATCH_1"
    system="$MATCH_2"
    type="$MATCH_3"
    branch="$MATCH_4"
    cat << EOF > "$DATADIR/workspace/$branch/test:morphs/$name.morph"
    name: $name
    kind: cluster
    systems:
    - morph: $system
      repo: test:morphs
      ref: $branch
      deploy:
        system:
          type: $type
    EOF

Implementations sections for reading error messages
===================================================

    IMPLEMENTS THEN the (branch|build|checkout|deploy|edit|init) error message includes the string "(.*)"
    grep "$MATCH_2" "$DATADIR/result-$MATCH_1"

IMPLEMENTS for test file and directory handling
===============================================

The IMPLEMENTS sections in this chapter create files and directories
for use as test data, and set and test their contents and permissions
and ownerships.

Create a directory
------------------

    IMPLEMENTS GIVEN a directory called (\S+)
    mkdir -p "$DATADIR/$MATCH_1"

Create a file
-------------

The file contents is used as a `printf`(1) format string.

    IMPLEMENTS GIVEN a file called (\S+) containing "(.*)"
    printf "$MATCH_2" > "$DATADIR/$MATCH_1"

Set attributes on a file or directory
-------------------------------------

    IMPLEMENTS GIVEN (\S+) is owned by uid (\S+)
    chown "$MATCH_2" "$DATADIR/$MATCH_1"

    IMPLEMENTS GIVEN (\S+) is owned by gid (\S+)
    chgrp "$MATCH_2" "$DATADIR/$MATCH_1"

    IMPLEMENTS GIVEN (\S+) has permissions (\S+)
    chmod "$MATCH_2" "$DATADIR/$MATCH_1"

Check attributes of a file on the filesystem
--------------------------------------------

    IMPLEMENTS THEN file (\S+) exists
    test -e "$DATADIR/$MATCH_1"

    IMPLEMENTS THEN file (\S+) has permissions (\S+)
    stat -c %A "$DATADIR/$MATCH_1" | grep -Fx -e "$MATCH_2"

    IMPLEMENTS THEN file (\S+) is owned by uid (\d+)
    stat -c %u "$DATADIR/$MATCH_1" | grep -Fx -e "$MATCH_2"

    IMPLEMENTS THEN file (\S+) is owned by gid (\d+)
    stat -c %g "$DATADIR/$MATCH_1" | grep -Fx -e "$MATCH_2"

    IMPLEMENTS THEN file (\S+) is empty
    stat -c %s "$DATADIR/$MATCH_1" | grep -Fx 0

Check contents of a file
------------------------

We treat the contents of the file in the step as a `printf`(1) format
string, to allow newlines and other such stuff to be expressed.

    IMPLEMENTS THEN file (\S+) contains "(.*)"
    printf "$MATCH_2" | diff - "$DATADIR/$MATCH_1"


IMPLEMENTS for running programs
===============================

This chapter contains IMPLEMENTS sections for running programs. It is
currently a bit of a placeholder.

Remember environment variables to set when running
--------------------------------------------------

We need to manage the environment. We store the extra environment
variables in `$DATADIR/env`. We treat the value as a format string for
`printf`(1) so that newlines etc can be used.

    IMPLEMENTS GIVEN an environment variable (\S+) containing "(.*)"
    printf "export $MATCH_1=$MATCH_2" >> "$DATADIR/env"

Implementations for building systems
------------------------------------

    IMPLEMENTS THEN morph build the system (\S+) of the (branch|tag) (\S+)
    cd "$DATADIR/workspace/$MATCH_3"
    run_morph build "$MATCH_1"

Implementations for tarball inspection
--------------------------------------

    IMPLEMENTS THEN tarball (\S+) contains (.*)
    tar -tf "$DATADIR/$MATCH_1" | grep -Fe "$MATCH_2"

    IMPLEMENTS THEN tarball (\S+) doesn't contain (.*)
    ! tar -tf "$DATADIR/$MATCH_1" | grep -Fe "$MATCH_2"

Implementations for morphology manipulation
==========================================

Altering morphologies in their source repositories
--------------------------------------------------

    IMPLEMENTS GIVEN system (\S+) uses (.+) from (\S+)
    "$SRCDIR/scripts/edit-morph" set-system-artifact-depends \
      "$DATADIR/gits/morphs/$MATCH_1.morph" "$MATCH_3" "$MATCH_2"
    run_in "$DATADIR/gits/morphs" git add "$MATCH_1.morph"
    run_in "$DATADIR/gits/morphs" git commit -m "Make $MATCH_1 only use $MATCH_2"

    IMPLEMENTS GIVEN stratum (\S+) has match rules: (.*)
    cd "$DATADIR/gits/morphs"
    "$SRCDIR/scripts/edit-morph" set-stratum-match-rules \
      "$MATCH_1.morph" "$MATCH_2"
    git add "$MATCH_1.morph"
    git commit -m "Make $MATCH_1 match $MATCH_2"

Altering morphologies in the workspace
--------------------------------------

    IMPLEMENTS GIVEN stratum (\S+) in system branch (\S+) has match rules: (.*)
    cd "$DATADIR/workspace/$MATCH_2/test:morphs"
    "$SRCDIR/scripts/edit-morph" set-stratum-match-rules \
      "$MATCH_1.morph" "$MATCH_3"