Software health reportschema 0.31.0 · metrics 2.10.0 · 2026-08-04 20:06 UTC

jhchen / fast-diff

A fast Javascript string diff

JavaScriptApache-2.0★ 715 stars⑂ 48 forkssince Oct 2014View on GitHub ↗

jhchen/fast-diff holds a health index of 33 out of 100, placing it in the At Risk band. It scores highest on Community & Adoption (69/100) and lowest on Vitality (1/100). It was last updated 1173 days ago. A single contributor accounts for most of its recent work.

overall / 100

At Risk

Software health index

Metrics are grouped into weighted categories on one standardized 1–100 scale. Overall starts as their weighted mean, calibrated against the distribution of the public record so bands carry percentile meaning; when public evidence triggers the High-Risk Jurisdiction Policy, the rating is adjusted and receives an At Risk ceiling of 34.

Exceptional93-100The record's top tier (≈ top 5%); essentially all checked criteria met

Excellent80-92Strong across the board; minor gaps

Good65-79Healthy; gaps are limited and manageable

Moderate50-64Acceptable with notable gaps; review recommended

Weak35-49Material weaknesses across several areas

At Risk20-34Significant weaknesses; adoption warrants caution

Critical1-19Severe problems (abandoned, single-maintainer, no hygiene)

Score profile

Each axis is a category. The shape matters more than the average — a healthy subject fills the whole shape, while a spike-and-crater profile means strength in one dimension is masking risk in another.

The weighted overall 38 is calibrated to 33 on the published index scale (record calibration 2026-08-02).

Ownership

Jason ChenPersonal account

625 followers12 public repossince Jan 2010@slab

This repository is owned by a personal account. A single-owner project carries more continuity risk than an organization-backed one.

Package ecosystems

Registry	Package	Version	Downloads / mo	Versions	Last publish	Tags
npm	fast-diff	1.3.0	202,964,355	7	1173 days ago	diff

Metrics by category

Vitality

Is the project alive — is code being written and are releases shipping?

1Critical · 21% of overall

Development activity

1Critical

How it's scored

0/36	Push recency — last push 1,173 days ago
0/36	Commit cadence — 0/52 weeks with commits
0/18	Commit volume — 0 commits in the last year
0/10	OpenSSF Scorecard: Maintained — 0 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 0

Inputs used

commits_last_year	0
human_commit_share	1
days_since_last_push	1,173
active_weeks_last_year	0

Release discipline

1Critical

How it's scored

0/27	Ships releases — no releases published
0/36	Release recency — no releases
0/27	Release cadence — no releases
0/10	OpenSSF Scorecard: Signed-Releases — no data

Inputs used

releases_count

Excluded from scoring (no data or not applicable): OpenSSF Scorecard: Signed-Releases. Remaining weights renormalized.

Community & Adoption

Does the project have users, downloads, attention, and a welcoming setup for contributors?

69Good · 17% of overall

Popularity & adoption

66Good

How it's scored

46.3/60	Stars — 715 stars
13.9/25	Forks — 48 forks
5.6/15	Watchers — 11 watchers

Inputs used

forks	48
stars	715
watchers	11
growth_state	unverified
growth_factor_pct	100
growth_unverified_reason	no_history

Community health

50Moderate

How it's scored

22.5/22.5	README
22.5/22.5	License — recognized license (Apache-2.0)
0/18	CONTRIBUTING guide
0/13.5	Code of conduct
0/7.2	Issue template
0/6.3	PR template

Inputs used

has_readme	yes
has_license	yes
readme_badges	1
has_contributing	no
has_issue_template	no
has_code_of_conduct	no
readme_badge_services	github.com
has_pull_request_template	no

Ecosystem adoption (downloads)

100Exceptional

How it's scored

80/80	Monthly downloads — 202,964,355 downloads/month across npm
0/20	Registry dependents — not reported by this ecosystem

Inputs used

packages	fast-diff
dependents	—
ecosystems	npm
total_downloads	—
monthly_downloads	202,964,355
unverified_packages_excluded	—

Excluded from scoring (no data or not applicable): Registry dependents. Remaining weights renormalized.

Sustainability & Governance

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep?

53Moderate · 23% of overall

Maintainer resilience (bus factor)

32At Risk

How it's scored

9/54	Bus factor — 1 contributor(s) cover half of all commits
7.9/22.5	Commit distribution — top contributor authored 65% of commits
5.4/13.5	Contributor breadth — 4 contributors
10/10	OpenSSF Scorecard: Contributors — project has 7 contributing companies or organizations

Inputs used

bus_factor	1
contributors_sampled	4
top_contributor_share	0.65

Issue & PR responsiveness

55Moderate

How it's scored

36/42	Issue resolution — 86% of issues closed
10/30	PR acceptance — 4/12 decided PRs merged
0/13	Newcomer PR acceptance — no first-time contributor's PR decided in 30d
1.5/15	OpenSSF Scorecard: Code-Review — Found 3/23 approved changesets -- score normalized to 1

Inputs used

merged_prs	4
open_issues	2
closed_issues	12
prs_merged_7d	0
prs_decided_7d	0
prs_merged_30d	0
prs_decided_30d	0
issue_closed_ratio	0.857
closed_unmerged_prs	8
first_time_authors_30d	0
first_time_prs_merged_30d	0
first_time_prs_decided_30d	0

Excluded from scoring (no data or not applicable): Newcomer PR acceptance. Remaining weights renormalized.

Ownership & stewardship

63Moderate

How it's scored

10/30	Ownership backing — personal (user) account
0/20	Verified domain — not applicable to user accounts
20.1/25	Owner reach — 625 followers of jhchen
20.1/25	Track record — 12 public repos, account ~16 yr old

Inputs used

followers	625
owner_type	User
is_verified	—
owner_login	jhchen
public_repos	12
account_age_days	6,030

Excluded from scoring (no data or not applicable): Verified domain. Remaining weights renormalized.

Package maintenance

69Good

How it's scored

25/25	Published & resolvable — 1 package(s) on npm
4/35	Publish recency — latest publish 1,173 days ago
20/20	Version history — 7 published versions
20/20	Not deprecated — active, not deprecated or yanked

Inputs used

packages	fast-diff
ecosystems	npm
any_deprecated	no
min_days_since_publish	1,173

Engineering Quality

Are baseline engineering and documentation practices in place?

34At Risk · 19% of overall

Engineering practices

24At Risk

How it's scored

24/24	CI workflows — 1 workflow(s)
0/24	Tests present
0/16	Linter config
0/9.6	Pre-commit hooks
0/6.4	.editorconfig
0/20	OpenSSF Scorecard: CI-Tests — 0 out of 4 merged PRs checked by a CI test -- score normalized to 0

Inputs used

has_ci	yes
has_tests	no
has_editorconfig	no
has_linter_config	no
has_precommit_config	no

Documentation

50Moderate

How it's scored

30/30	README
0/25	Documentation directory
0/15	Documentation / homepage site
10/10	Repository description
0/10	Topics
10/10	Wiki

Inputs used

topics	—
has_wiki	yes
homepage	—
docs_site	—
has_readme	yes
has_docs_dir	no
has_description	yes

Security

Are visible security and supply-chain practices strong, without unresolved high-risk jurisdiction exposure?

40Weak · 16% of overall

Security posture

25At Risk

How it's scored

7.5/7.5	Binary-Artifacts — no binaries found in the repo
0/7.5	Branch-Protection — branch protection not enabled on development/release branches
0/2.5	CI-Tests — 0 out of 4 merged PRs checked by a CI test -- score normalized to 0
0/2.5	CII-Best-Practices — no effort to earn an OpenSSF best practices badge detected
0.8/7.5	Code-Review — Found 3/23 approved changesets -- score normalized to 1
2.5/2.5	Contributors — project has 7 contributing companies or organizations
10/10	Dangerous-Workflow — no dangerous workflow patterns detected
0/7.5	Dependency-Update-Tool — no update tool detected
0/5	Fuzzing — project is not fuzzed
2.5/2.5	License — license file detected
0/7.5	Maintained — 0 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 0
0/5	Packaging — no data
0/5	Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 0
0/5	SAST — SAST tool is not run on all commits -- score normalized to 0
0/5	Security-Policy — security policy file not detected
0/7.5	Signed-Releases — no data
0/7.5	Token-Permissions — detected GitHub workflow tokens with excessive permissions
0/7.5	Vulnerabilities — 19 existing vulnerabilities detected

Inputs used

source	openssf_scorecard
checks_evaluated	16
scorecard_version	v5.5.0
checks_inconclusive	2
scorecard_aggregate	2.5

Excluded from scoring (no data or not applicable): Packaging, Signed-Releases. Remaining weights renormalized.

Dependency advisories

100Exceptional

How it's scored

35/35	Direct dependencies free of known advisories — no direct dependency carries a known advisory
0/25	Indirect dependencies free of known advisories — transitive set not separable from development and test dependencies in this scope
0/40	No advisories left outstanding — no advisory carries a publication date

Inputs used

source	osv
advisories	20
affected_packages	10
assessed_packages	154
unassessed_packages	0
affected_by_severity	critical 1, high 7, moderate 1, low 1
direct_affected_packages	0

Excluded from scoring (no data or not applicable): Indirect dependencies free of known advisories, No advisories left outstanding. Remaining weights renormalized. Matched 154 resolved dependencies against OSV. This repository publishes no package the index resolves, so the repository dependency graph was assessed instead. That graph mixes development and test pins with shipped dependencies, so only the declared runtime dependencies are scored; transitive findings are reported as context and excluded from the score. Reachability is not analyzed.

AI Readiness

How well is the repo equipped to be developed and maintained with AI coding agents? Carries a deliberately small weight (4%): agent tooling is a real maintenance signal, but a repository with none can still reach 100/100.

15Critical · 4% of overall

Agent context & guidance

3Critical

How it's scored

0/45	Agent instructions — no CLAUDE.md / AGENTS.md / editor rules
0/15	Machine-readable docs (llms.txt)
2.7/40	Legible commit history — 2 of 40 human commits state their intent (structured subject or explanatory body)

Inputs used

has_llms_txt	no
llms_txt_url	—
legible_history_share	0.05
agent_instruction_files	—
agent_instruction_max_bytes	—

Verify loop (build / test / typecheck)

10Critical

How it's scored

0/18	One-command bootstrap
0/22	Automated tests
0/11	Lint / format config
0/11	Static type checking
10/10	Reproducible environment — lockfile
0/10	Demonstrated agent practice — no agent-authored commits among the last 40
0/8	Automated maintenance — no automated dependency updates observed
0/10	OpenSSF Scorecard: Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 0

Inputs used

has_nix	no
has_tests	no
lockfiles	package-lock.json
has_dockerfile	no
typed_language	no
bootstrap_files	—
has_devcontainer	no
has_linter_config	no
typecheck_configs	—
agent_commit_share	0
toolchain_manifests	—
dependency_bot_commit_share	0

Code legibility for models

55Moderate

How it's scored

0/45	Type-checkable code — JavaScript without a type-check config
55/55	Manageable file sizes — 0/3 source files over 60KB

Inputs used

primary_language	JavaScript
largest_source_bytes	38,838
source_files_sampled	3
oversized_source_files	0

Key facts

715GitHub stars

4contributors

0commits, last 12 months

1,173days since last push

0releases

1bus factor

2open issues

npmpackage ecosystems

Data collection warnings

Star history unavailable: GitHub GraphQL error: Resource not accessible by personal access token

More detail

Star and fork history 0 ★ / 48 ⇿

0Stars

48Forks

When each star and fork was added, collected from GitHub and bucketed by day. Cumulative growth sits directly above the daily additions it is made of, so the two read against each other: steady organic accretion looks nothing like an abrupt, short-lived burst. Where that difference is measurable, it is reported as growth authenticity.

Each point covers 11 days.

OpenSSF Scorecard 2.5 / 10

2.5aggregate

Independent, tool-agnostic security assessment from the open-source OpenSSF Scorecard. Each check rewards a security practice, not a specific vendor's tool. Checks Scorecard could not determine are marked n/a and excluded from the security score (never counted as zero).Scorecard v5.5.0 · 2026-08-04 20:06 UTC

10	Binary-Artifacts	no binaries found in the repo
0	Branch-Protection	branch protection not enabled on development/release branches
0	CI-Tests	0 out of 4 merged PRs checked by a CI test -- score normalized to 0
0	CII-Best-Practices	no effort to earn an OpenSSF best practices badge detected
1	Code-Review	Found 3/23 approved changesets -- score normalized to 1
10	Contributors	project has 7 contributing companies or organizations
10	Dangerous-Workflow	no dangerous workflow patterns detected
0	Dependency-Update-Tool	no update tool detected
0	Fuzzing	project is not fuzzed
10	License	license file detected
0	Maintained	0 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 0
n/a	Packaging	packaging workflow not detected
0	Pinned-Dependencies	dependency not pinned by hash detected -- score normalized to 0
0	SAST	SAST tool is not run on all commits -- score normalized to 0
0	Security-Policy	security policy file not detected
n/a	Signed-Releases	no releases found
0	Token-Permissions	detected GitHub workflow tokens with excessive permissions
0	Vulnerabilities	19 existing vulnerabilities detected

All dependencies 154

Full resolved dependency set from the GitHub dependency graph: 0 direct and 154 indirect (transitive) packages. The transitive closure is complete when the repository commits a lockfile.

Registry	Package	Version	Relation
npm	@ampproject/remapping	`2.2.1`	indirect
npm	@babel/code-frame	`7.21.4`	indirect
npm	@babel/compat-data	`7.21.4`	indirect
npm	@babel/core	`7.21.4`	indirect
npm	@babel/generator	`7.21.4`	indirect
npm	@babel/helper-compilation-targets	`7.21.4`	indirect
npm	@babel/helper-environment-visitor	`7.18.9`	indirect
npm	@babel/helper-function-name	`7.21.0`	indirect
npm	@babel/helper-hoist-variables	`7.18.6`	indirect
npm	@babel/helper-module-imports	`7.21.4`	indirect
npm	@babel/helper-module-transforms	`7.21.2`	indirect
npm	@babel/helper-simple-access	`7.20.2`	indirect
npm	@babel/helper-split-export-declaration	`7.18.6`	indirect
npm	@babel/helper-string-parser	`7.19.4`	indirect
npm	@babel/helper-validator-identifier	`7.19.1`	indirect
npm	@babel/helper-validator-option	`7.21.0`	indirect
npm	@babel/helpers	`7.21.0`	indirect
npm	@babel/highlight	`7.18.6`	indirect
npm	@babel/parser	`7.21.4`	indirect
npm	@babel/template	`7.20.7`	indirect
npm	@babel/traverse	`7.21.4`	indirect
npm	@babel/types	`7.21.4`	indirect
npm	@istanbuljs/load-nyc-config	`1.1.0`	indirect
npm	@istanbuljs/schema	`0.1.3`	indirect
npm	@jridgewell/gen-mapping	`0.3.3`	indirect
npm	@jridgewell/resolve-uri	`3.1.0`	indirect
npm	@jridgewell/set-array	`1.1.2`	indirect
npm	@jridgewell/sourcemap-codec	`1.4.14`	indirect
npm	@jridgewell/sourcemap-codec	`1.4.15`	indirect
npm	@jridgewell/trace-mapping	`0.3.18`	indirect
npm	aggregate-error	`3.1.0`	indirect
npm	ansi-regex	`5.0.1`	indirect
npm	ansi-styles	`3.2.1`	indirect
npm	ansi-styles	`4.3.0`	indirect
npm	append-transform	`2.0.0`	indirect
npm	archy	`1.0.0`	indirect
npm	argparse	`1.0.10`	indirect
npm	balanced-match	`1.0.2`	indirect
npm	brace-expansion	`1.1.11`	indirect
npm	browserslist	`4.21.5`	indirect
npm	caching-transform	`4.0.0`	indirect
npm	camelcase	`5.3.1`	indirect
npm	caniuse-lite	`1.0.30001478`	indirect
npm	chalk	`2.4.2`	indirect
npm	clean-stack	`2.2.0`	indirect
npm	cliui	`6.0.0`	indirect
npm	color-convert	`1.9.3`	indirect
npm	color-convert	`2.0.1`	indirect
npm	color-name	`1.1.3`	indirect
npm	color-name	`1.1.4`	indirect
npm	commondir	`1.0.1`	indirect
npm	concat-map	`0.0.1`	indirect
npm	convert-source-map	`1.9.0`	indirect
npm	cross-spawn	`7.0.3`	indirect
npm	debug	`4.3.4`	indirect
npm	decamelize	`1.2.0`	indirect
npm	default-require-extensions	`3.0.1`	indirect
npm	electron-to-chromium	`1.4.365`	indirect
npm	emoji-regex	`8.0.0`	indirect
npm	es6-error	`4.1.1`	indirect
npm	escalade	`3.1.1`	indirect
npm	escape-string-regexp	`1.0.5`	indirect
npm	esprima	`4.0.1`	indirect
npm	find-cache-dir	`3.3.2`	indirect
npm	find-up	`4.1.0`	indirect
npm	foreground-child	`2.0.0`	indirect
npm	fromentries	`1.3.2`	indirect
npm	fs.realpath	`1.0.0`	indirect
npm	gensync	`1.0.0-beta.2`	indirect
npm	get-caller-file	`2.0.5`	indirect
npm	get-package-type	`0.1.0`	indirect
npm	glob	`7.2.3`	indirect
npm	globals	`11.12.0`	indirect
npm	graceful-fs	`4.2.11`	indirect
npm	has-flag	`3.0.0`	indirect
npm	has-flag	`4.0.0`	indirect
npm	hasha	`5.2.2`	indirect
npm	html-escaper	`2.0.2`	indirect
npm	imurmurhash	`0.1.4`	indirect
npm	indent-string	`4.0.0`	indirect
npm	inflight	`1.0.6`	indirect
npm	inherits	`2.0.4`	indirect
npm	is-fullwidth-code-point	`3.0.0`	indirect
npm	is-stream	`2.0.1`	indirect
npm	is-typedarray	`1.0.0`	indirect
npm	is-windows	`1.0.2`	indirect
npm	isexe	`2.0.0`	indirect
npm	istanbul-lib-coverage	`3.2.0`	indirect
npm	istanbul-lib-hook	`3.0.0`	indirect
npm	istanbul-lib-instrument	`4.0.3`	indirect
npm	istanbul-lib-processinfo	`2.0.3`	indirect
npm	istanbul-lib-report	`3.0.0`	indirect
npm	istanbul-lib-source-maps	`4.0.1`	indirect
npm	istanbul-reports	`3.1.5`	indirect
npm	js-tokens	`4.0.0`	indirect
npm	js-yaml	`3.14.1`	indirect
npm	jsesc	`2.5.2`	indirect
npm	json5	`2.2.3`	indirect
npm	locate-path	`5.0.0`	indirect
npm	lodash	`4.17.21`	indirect
npm	lodash.flattendeep	`4.4.0`	indirect
npm	lru-cache	`5.1.1`	indirect
npm	make-dir	`3.1.0`	indirect
npm	minimatch	`3.1.2`	indirect
npm	ms	`2.1.2`	indirect
npm	node-preload	`0.2.1`	indirect
npm	node-releases	`2.0.10`	indirect
npm	nyc	`15.1.0`	indirect
npm	once	`1.4.0`	indirect
npm	p-limit	`2.3.0`	indirect
npm	p-locate	`4.1.0`	indirect
npm	p-map	`3.0.0`	indirect
npm	p-try	`2.2.0`	indirect
npm	package-hash	`4.0.0`	indirect
npm	path-exists	`4.0.0`	indirect
npm	path-is-absolute	`1.0.1`	indirect
npm	path-key	`3.1.1`	indirect
npm	picocolors	`1.0.0`	indirect
npm	pkg-dir	`4.2.0`	indirect
npm	process-on-spawn	`1.0.0`	indirect
npm	release-zalgo	`1.0.0`	indirect
npm	require-directory	`2.1.1`	indirect
npm	require-main-filename	`2.0.0`	indirect
npm	resolve-from	`5.0.0`	indirect
npm	rimraf	`3.0.2`	indirect
npm	seedrandom	`3.0.5`	indirect
npm	semver	`6.3.0`	indirect
npm	set-blocking	`2.0.0`	indirect
npm	shebang-command	`2.0.0`	indirect
npm	shebang-regex	`3.0.0`	indirect
npm	signal-exit	`3.0.7`	indirect
npm	source-map	`0.6.1`	indirect
npm	spawn-wrap	`2.0.0`	indirect
npm	sprintf-js	`1.0.3`	indirect
npm	string-width	`4.2.3`	indirect
npm	strip-ansi	`6.0.1`	indirect
npm	strip-bom	`4.0.0`	indirect
npm	supports-color	`5.5.0`	indirect
npm	supports-color	`7.2.0`	indirect
npm	test-exclude	`6.0.0`	indirect
npm	to-fast-properties	`2.0.0`	indirect
npm	type-fest	`0.8.1`	indirect
npm	typedarray-to-buffer	`3.1.5`	indirect
npm	update-browserslist-db	`1.0.10`	indirect
npm	uuid	`8.3.2`	indirect
npm	which	`2.0.2`	indirect
npm	which-module	`2.0.0`	indirect
npm	wrap-ansi	`6.2.0`	indirect
npm	wrappy	`1.0.2`	indirect
npm	write-file-atomic	`3.0.3`	indirect
npm	y18n	`4.0.3`	indirect
npm	yallist	`3.1.1`	indirect
npm	yargs	`15.4.1`	indirect
npm	yargs-parser	`18.1.3`	indirect

Dependency advisories 10

This repository publishes no package the index resolves, so its own dependency graph was assessed — 154 packages, which also include development and test pins that never ship: 10 carry known advisories, of which 0 are direct.

Package	Version	Relation	Severity	Advisories	Fixed in
@babel/traverse	`7.21.4`	indirect	critical	1	`8.0.0-alpha.4`
brace-expansion	`1.1.11`	indirect	high	5	`5.0.9`
cross-spawn	`7.0.3`	indirect	high	1	`7.0.5`
js-yaml	`3.14.1`	indirect	high	3	`4.3.0`
lodash	`4.17.21`	indirect	high	3	`4.18.0`
minimatch	`3.1.2`	indirect	high	3	`10.2.3`
semver	`6.3.0`	indirect	high	1	`7.5.2`
uuid	`8.3.2`	indirect	high	1	`13.0.1`
@babel/helpers	`7.21.0`	indirect	moderate	1	`8.0.0-alpha.17`
@babel/core	`7.21.4`	indirect	low	1	`8.0.0-rc.6`

An advisory means the version recorded in the dependency graph falls inside an advisory’s affected range. Reachability is not analysed, and the graph includes development and test pins — a finding may concern tooling rather than shipped software.

Raw JSON report machine-readable

Feedback

Spotted something off in this report, or have thoughts to share? Wrong measurements, missed tooling, ideas, questions — anything is welcome. Every message is read and gets a response.

Scores are signals, not warranties. They reflect publicly visible practices on GitHub — not a code audit, and not a security guarantee.

Missing data is excluded and weights renormalized, never scored as zero. Methodology is versioned and open: metrics v2.10.0, schema v0.31.0 — full methodology · metrics wiki.

How one result sits in the wider record: aggregate statistics — npm.

Software health index

Score profile

Ownership

Package ecosystems

Metrics by category

Key facts

Data collection warnings

More detail

Feedback

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