ネットワークが見つけたもの
以下の各行は意見ではなく測定です。いずれも公開サンプルにリンクしており、その contract はネットワークを切った固定コンテナで実行されるので、自分で再実行して結果に反論できます。
OS とランタイムはリンク先サンプルに記録された環境です。その項目がない記録は選択時に除外されます。
597 件の発見、8 個のエコシステム。
- cargo
- composer
- gem
- golang
- hex
- npm
- pub
- pypi
サンプルが述べ、その契約が測ったこと
公開サンプルが測定した結果の 501–525 件目(全 568 件)。
-
npmサンプル契約node · linux/x64@babel/core@8.0.1
信じられていることTargeting an environment with known JavaScript engine bugs forces preset-env to downlevel the surrounding modern ES2015+ syntax categories down to ES5 helper functions.
測定結果preset-env targeting Safari 14 preserves native ES2015 destructuring syntax and parameter defaults while surgically renaming only the colliding parameter identifier to avoid JavaScriptCore scope shadowing bugs
-
npmサンプル契約node · linux/x64@babel/preset-env@7.29.7
信じられていることLeaving useBuiltIns unset in @babel/preset-env automatically injects polyfills for unsupported ECMAScript standard library methods across configured target environments when corejs is configured or core-js is imported.
測定結果When useBuiltIns is unset, @babel/preset-env defaults to false and leaves standard library methods un-polyfilled without injecting any core-js imports, even when targets lack support or corejs is specified.
-
npmサンプル契約node · linux/x64@babel/preset-env@8.0.2
信じられていることIn Babel presets, legacy configuration options like loose, spec, bugfixes, and useBuiltIns remain accepted as valid options, and isPluginRequired continues to be exported as a helper function.
測定結果Passing loose, spec, bugfixes, or useBuiltIns to @babel/preset-env in major version 8 throws descriptive removal errors rather than accepting legacy configuration options or polyfill strategies.
-
composerサンプル契約php · linux/x64symfony/console@8.1.4
信じられていることSubclassing Command with a static getDefaultName method automatically defines the command name on instantiation, and closures assigned via setCode may omit explicit integer return values.
測定結果Command subclasses defining static getDefaultName() have a null name in Symfony Console 8 because getDefaultName() was removed in favor of #[AsCommand], and Application::addCommand() throws LogicException for empty names.
-
npmサンプル契約node · linux/x64@rollup/plugin-commonjs@29.0.3
信じられていることWhen bundling CommonJS modules that conditionally require Node built-ins into ESM, @rollup/plugin-commonjs preserves lazy evaluation inside functions without hoisting static imports to the module top level.
測定結果By default, @rollup/plugin-commonjs hoists conditional require('node:fs') calls to top-level ESM static imports, eagerly loading built-in modules on startup rather than preserving lazy CommonJS evaluation.
-
npmサンプル契約node · linux/x64@rollup/plugin-commonjs@28.0.9
信じられていることBy default @rollup/plugin-commonjs transforms require expressions into bundled module imports in any file processed by Rollup.
測定結果assert requireReturnsDefault defaults to false, returning an augmented namespace object with __esModule marker rather than unwrapping default export directly when CJS requires ESM
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることA good model expects CSV to inherit its default `row_sep` from `$INPUT_RECORD_SEPARATOR` whenever `row_sep` is not passed.
測定結果assert that setting `$INPUT_RECORD_SEPARATOR` to "|" and calling `CSV.new("a,b")` yields `row_sep == "\n"`
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることThe CSV :numeric and :integer converters parse numeric string values using base-10 decimal representation.
測定結果CSV.parse_line with converters: :numeric parses leading-zero strings like 012 as octal integer 10, whereas strings with non-octal digits like 008 fall through to float 8.0 rather than parsing as decimal integers or strings
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることCSV.parse treats an input IO stream as caller-managed and leaves it open after parsing, while CSV.open and CSV.foreach automatically release underlying file handles.
測定結果CSV.parse(io) without a block permanently closes the caller-provided IO or StringIO stream upon completion, whereas CSV.parse(io) with a block leaves the stream open
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることCalling CSV.instance twice with the same source should create independent parser state that starts from the beginning each time.
測定結果CSV.instance caches one parser per source object and option set, so the second call with the same source reuses the first parser's cursor instead of starting over.
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることPassing converters: :numeric parses numeric strings with leading zeros as decimal numbers or preserves them consistently as strings.
測定結果CSV.parse_line with converters: :numeric parses leading-zero strings with octal digits 0-7 as octal integers while strings containing 8 or 9 fall back to floats, mutating 0123 into 83 and 0890 into 890.0 across a round trip
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることCSV::InvalidEncodingError inherits from Ruby core's EncodingError, and liberal_parsing: true suppresses unclosed quote errors.
測定結果CSV::InvalidEncodingError inherits from CSV::MalformedCSVError and RuntimeError rather than EncodingError, so rescue EncodingError fails to catch byte sequence errors during parsing.
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることCSV.parse returns empty strings for unquoted empty fields between delimiters by default.
測定結果assert parsing unquoted empty fields returns nil rather than empty string when nil_value is left unset
-
gemサンプル契約ruby · linux/x64csv@3.3.2
信じられていることA developer expects duplicated header values to follow normal Ruby Hash last-wins semantics when using CSV row conversion.
測定結果CSV.parse("id,id,name\n1,2,alice\n", headers: true).first.to_h["id"] evaluates to "1", not "2", because CSV::Row#to_h preserves the first duplicate header.
-
cargoサンプル契約rust · linux/x64winnow@1.0.4
信じられていることCalling `Parser::default_value()` makes a parser yield the default value whenever the wrapped parser fails.
測定結果assert `alpha1.default_value()` on '123' returns `Err(ErrMode::Backtrack(_))` instead of falling back to `0`
-
npmサンプル契約node · linux/x64@babel/core@8.0.1
信じられていることloadPartialConfig({...}) returns a PartialConfig object synchronously, because that is how every Babel 7 example, README snippet, and tool integration calls it; the callback form was always optional.
測定結果Calling loadPartialConfig() without a callback in Babel 8 throws an Error whose message names loadPartialConfigSync as the required synchronous replacement — in Babel 7 the identical call returned a PartialConfig object without throwing.
-
hexサンプル契約elixir · linux/x64nimble_csv@1.3.0
信じられていることWhen a parser is defined with separator: ["|", ";"], dumping rows that were parsed from semicolon-delimited input will preserve the semicolon separator, because the parser accepted that format.
測定結果Parsing semicolon-separated CSV with a multi-separator parser succeeds, but dump_to_iodata emits pipe-separated output — the first separator in the list — not the semicolon the input used, because the dump separator is fixed at compile time by the first list entry.
-
hexサンプル契約elixir · linux/x64nimble_pool@1.1.0
信じられていることA model expects that starting a lazy pool with lazy: true defers worker module validation until checkout, allowing start_link to return {:ok, pid} even when given an unresolvable worker module or an atom :infinity for pool_size.
測定結果NimblePool.start_link/1 with lazy: true eagerly ensures the worker module is loaded in init/1 and fails pool startup with an ArgumentError when the module is not found.
-
hexサンプル契約elixir · linux/x64ecto@3.12.5
信じられていることEcto.Multi.run/3 accepts a single-argument callback receiving the accumulated changes map, matching other Multi dynamic callbacks and Ecto 2 conventions.
測定結果assert Ecto.Multi.run/3 requires a 2-arity function taking repo and changes and raises FunctionClauseError on a 1-arity function, whereas Multi.insert/3 and Multi.merge/2 accept 1-arity functions receiving only changes
-
golangサンプル契約go · linux/x64net/http@go1.26.5
信じられていることOnce net/http drops Authorization for a cross-domain redirect, the header stays absent for the rest of the chain — but before go1.23.7 / go1.24.1, a same-domain hop immediately following a cross-domain hop silently restores Authorization to the request, leaking the credential to the second domain while the HTTP response stays 200.
測定結果After a three-hop redirect chain where the first cross-domain hop strips Authorization, the Authorization header must be absent at the same-domain second hop on serverB — before go1.23.7 / go1.24.1 this assertion fails silently with a 200 response.
-
golangサンプル契約go · linux/x64net/http@v1.26.5
信じられていることSetting http.Transport.MaxIdleConns to a high value allows all idle connections to a single target host to be pooled when MaxIdleConnsPerHost is left unset.
測定結果Leaving http.Transport.MaxIdleConnsPerHost unset (0) with MaxIdleConns set to 100 retains only 2 idle connections for a host, rejecting the 3rd connection with 'too many idle connections for host'.
-
golangサンプル契約go · linux/x64net/http@go1.22.0
信じられていることReadHeaderTimeout enforces a deadline on reading the request body
測定結果the server handler takes >2s to read the request body despite ReadHeaderTimeout=1s
-
golangサンプル契約go · linux/x64net/http@v1.26.5
信じられていることCalling resp.Body.Close() — the pattern shown in every tutorial — is sufficient for http.Transport to reclaim and reuse the underlying TCP connection for the next request.
測定結果When resp.Body.Close() is called without draining the body first, http.Transport opens a brand-new TCP connection for the very next request to the same host, measured via httptrace.GotConnInfo.Reused being false.
-
golangサンプル契約go · linux/x64net/http@v1.26.5
信じられていることA second request on the same `http.Client` should proceed after the first `Do` call returns, even if that first response body is never read or closed.
測定結果A second request using the same `http.Client` and `http.Transport{MaxConnsPerHost: 1}` does not complete while the first response body remains open, returning a context timeout instead.
-
golangサンプル契約go · linux/x64net/http@go1.26.5
信じられていることA setting named `GODEBUG=http2server=0` only affects debug output, so an explicit HTTP/2-only setup should still work.
測定結果An HTTP/2-only client-server pair should negotiate and return `HTTP/2.0` by default, while the same code with `GODEBUG=http2server=0` must fail because no shared protocol is available.
ここの行を確かめる方法
サンプルを開き、contract を読み、実行してください。contract はそのサンプル自身のテストです。ネットワークを切った固定コンテナで実行され、その実行の署名済みレシートがネットワークに保存されます。ここに書かれていることはライブラリについての解釈ではなく、ライブラリが実際に行ったことだけに基づいています。
公開済みのサンプルのうち、このページにないものがあります。契約は通過しておりサンプルも生きていますが、その契約に文として読める行がないからです。expect(x).toBe(1) のような断言は、検査している思い込みの隣に置いても読者に何も伝えません。読めない証拠を載せるより、空けておくことを選びました。