Address emscripten dependency in tree-sitter-xpath

[eyelidlessness]

It must have slipped my mind that emscripten is an external dependency for tree-sitter-xpath. I'd originally hoped to address this by making it a package dependency. I believe that may be possible (despite the tree-sitter documentation suggesting otherwise), but if I recall I deferred addressing it before other tooling dust had settled. Either way it should be addressed, either by inclusion in package install or by explicit documentation.

[eyelidlessness]

I did a brief spike into managing this with yarn like we manage pretty much everything else. This seemed like it would work:

1. Install emscripten-sdk-npm (by git reference to current commit in, as a necessary fix was never published)
2. Run:

yarn emsdk-checkout
yarn emsdk install latest # Note: if we do this for real, we'd want to specify a version
yarn emsdk activate latest # ^

3. Run the source command provided in the output from the above commands, which adds the locally installed/activated.

At this point I just verified that which emcc pointed to a path below node_modules. The intent of the spike was to see if we could trivially address this in getodk/web-forms#116 before first publish. I held off going any further with than that for that PR because:

• It's sufficiently manual that we'd want to script it
• We'd probably want to consider some way of making it optional for environments where Emscripten is already present (which seems to be the case in CI!)

But I wanted to leave these breadcrumbs here for when we come back to setup instructions, in case we do think it'd be valuable to automate this aspect of extraneous dependency setup for that.

[latin-panda]

I’ve been working on running the visual tests in Docker but ran into issues building the tree-sitter package. After some trial and error, I managed to get past the build by adding Emscripten and other dependencies in the first Dockerfile stage.

Snapshot of Dockerfile stage

FROM node:22.12.0-slim AS builder

WORKDIR /app

RUN apt-get update && apt-get install -y \
    python3 \
    make \
    g++ \
    curl \
    git \
    cmake \
    xz-utils \
    openjdk-17-jre-headless \
    && rm -rf /var/lib/apt/lists/*

COPY package.json yarn.lock ./
RUN yarn install --frozen-lockfile --production

COPY . .

# RUN yarn install --frozen-lockfile 

RUN git clone https://github.com/emscripten-core/emsdk.git /emsdk && \
    cd /emsdk && \
    ./emsdk install latest && \
    ./emsdk activate latest

RUN cd /emsdk && \
    . ./emsdk_env.sh && \
    cd /app && \
    yarn build --force

@garethbowen and other teammates mentioned similar setup troubles and shared a Slack thread discussing potential improvements. One idea from that thread was committing the compiled JS, but we agreed that making the build process reliable is a better long-term solution. We might also consider adding a helper script to simplify dependency setup, that would be more of a temporary patch than a real fix.

[latin-panda]

@garethbowen what do you think about moving this one to shelve? It doesn't seem we are targeting this one for 1.0.0 or 1.1.0

[garethbowen]

Sure.