Check license script fails in npm version 7.6.0

[fluiddot]

Description

Running the command npm run check-licenses in npm version 7.6.0 fails with the following error:

[1] undefined:1
[1]
[1]
[1]
[1] SyntaxError: Unexpected end of JSON input
[1]     at JSON.parse (<anonymous>)
[1]     at Object.<anonymous> (<WORKSPACE_DIR>/gutenberg/packages/scripts/scripts/check-licenses.js:188:21)
[1]     at Module._compile (internal/modules/cjs/loader.js:1063:30)
[1]     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
[1]     at Module.load (internal/modules/cjs/loader.js:928:32)
[1]     at Function.Module._load (internal/modules/cjs/loader.js:769:14)
[1]     at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
[1]     at internal/main/run_main_module.js:17:47
[1] wp-scripts check-licenses --dev exited with code 1
[0] undefined:1
[0]
[0]
[0]
[0] SyntaxError: Unexpected end of JSON input
[0]     at JSON.parse (<anonymous>)
[0]     at Object.<anonymous> (<WORKSPACE_DIR>/gutenberg/packages/scripts/scripts/check-licenses.js:188:21)
[0]     at Module._compile (internal/modules/cjs/loader.js:1063:30)
[0]     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
[0]     at Module.load (internal/modules/cjs/loader.js:928:32)
[0]     at Function.Module._load (internal/modules/cjs/loader.js:769:14)
[0]     at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12)
[0]     at internal/main/run_main_module.js:17:47
[0] wp-scripts check-licenses --prod --gpl2 --ignore=@react-native-community/cli,@react-native-community/cli-platform-ios exited with code 1

The error looks like it's related to the command npm ls that is used for fetching all the dependencies data.

I tried to run npm ls --json --all to check the output of that command and it's giving a lot of error like the following ones:

npm ERR! code ELSPROBLEMS
npm ERR! missing: sveltedoc-parser@^3.0.4, required by @storybook/addon-docs@6.1.11
npm ERR! missing: vue@^2.6.10, required by @storybook/addon-docs@6.1.11
npm ERR! missing: canvas@^2.5.0, required by jsdom@16.4.0
npm ERR! invalid: react-refresh@0.4.2 <WORKSPACE_DIR>/gutenberg/node_modules/react-refresh
...

Step-by-step reproduction instructions

1. Install npm version 7.6.0 (you can run the command: npm install -g npm@7.6.0
2. Remove <7 condition from the npm engine section of package.json file (example)
3. Run npm run check-licenses
4. Observe that the script fails

Expected behaviour

Running the script should succeed.

Actual behaviour

Running the script produces an error.

Screenshots or screen recording (optional)

N/A

Code snippet (optional)

WordPress information

• WordPress version: N/A
• Gutenberg version: 10.0.1
• Are all plugins except Gutenberg deactivated? N/A
• Are you using a default theme (e.g. Twenty Twenty-One)? N/A

Device information

• Device: N/A
• Operating system: N/A
• Browser: N/A

[fluiddot]

I found this issue in npm/cli that describes a similar problem.

[gziolo]

As tested in #33892, it's no longer an issue with the most recent version of npm v7.